Posters Program

Posters Scope and Goals

The IEEE Quantum Week Posters program presents excellent opportunities for graduate students, undergraduate students, researchers, practitioners, entrepreneurs, and start-ups to showcase their work and engage with the international quantum computing R&D community during IEEE Quantum Week. Posters are intended to stimulate discussions of recent advances, experiences, and challenges in quantum computing and engineering. 

Posters Chair and Contact

Ulrike Stege, University of Victoria — ustege@uvic.

Posters Program

 

QCE21 Posters — Overview

Poster Session 1: Mon, Oct 18 @ 10:00-10:45

Variational Quantum Algorithm for Eigenvalue Problems of a Class of Schrödinger-type Partial Differential Equations
Paula García-Molina, Javier Rodríguez-Mediavilla, Juan José García-Ripoll (Inst. De Física)
Detecting Energy Levels of Spin Systems on IBM's Quantum Computer by Evolution of Mean Value of Physical Quantity
Khrystyna Gnatenko (Ivan Franko National Univ. of Lviv), Hanna Laba (Lviv Polytechnic National Univ.), Volodymyr Tkachuk (Ivan Franko National Univ. of Lviv))

Poster Session 2: Mon, Oct 18 @ 12:15-13:00

Implementing the Simplex Method with Grover's Search
Adeline Jordon, Saasha Joshi, Prashanti Priya Angara (Univ. of Victoria)

Poster Session 3: Mon, Oct 18 @ 14:30-15:15

Simulation of Continuous-Variable Quantum Systems with Tensor Network
Ryutaro Nagai (blueqat inc.), Takao Tomono (Toppan Inc.), Yuichiro Minato (blueqat inc.)
Optimistic Entanglement Purification with few Quantum Memories
Mohammad Mobayenjarihani (Univ. of Massachusetts Amherst), Gayane Vardoyan (Delft Univ. of Technology), Donald Towsley (Univ. of Massachusetts Amherst)

Poster Session 4: Tue, Oct 19 @ 10:00-10:45

qopt: An experiment-oriented Qubit Simulation and Quantum Optimal Control Package
Julian Teske, Hendrik Bluhm (Forschungszentrum Jülich GmbH)
Open-source Multi-channel Smart Arbitrary Waveform Generators (SAWG) for Quantum Information Processing
David Allcock (Univ. of Oregon & NIST), Christopher Balance (Univ. of Oxford), Sébastien Bourdeauducq (M-Labs Ltd.), Joseph Britton (Army Research Lab.), Michał Gąska (Warsaw Univ. of Technology), Thomas Harty (Univ. of Oxford), Jakub Jarosiński (Warsaw Univ. of Technology), Robert Jördens (QUARTIQ GmbH), Grzegorz Kasprowicz (Warsaw Univ. of Technology), Norman Krackow (M-Labs Ltd.), Paweł Kulik (Warsaw Univ. of Technology), David Nadlinger (Univ. of Oxford), Dorota Nowicka, Krzysztof Późniak, Tomasz Przywózki (Warsaw Univ. of Technology), Daniel Slichter (QUARTIQ GmbH), Mikołaj Sowiński (Warsaw Univ. of Technology), Marius Weber, Weida Zhang (Univ. of Oxford)

Poster Session 5: Tue, Oct 19 @ 12:15-13:00

Joint Parity-Time and Anti-Parity-Time-symmetric Qubits
Julia Cen, Avadh Saxena (Los Alamos National Lab)
On Generating a Probability Distribution Amenable to NISQ Using Modifications to Grover’s Algorithm
Sayantan Pramanik, M Girish Chandra (Tata Consultancy Services)

Poster Session 6: Tue, Oct 19 @ 14:30-15:15

A Low-noise and Scalable FPGA-based Analog Signal Generator for Quantum Gas Experiments
David Pahl, Lukas Pahl, Enis Mustafa, Zhenning Liu, Philipp Fabritius, Jeffrey Mohan, Peter Clements, Abdulkadir Akin, Tilman Esslinger (ETH Zurich)
Optimal Policies for Distributed Quantum Computing in Quantum Walk Control Plane Protocol
Matheus Guedes de Andrade, Wenhai Dai, Don Towsley (Univ. of Massachusetts Amherst), Saikat Guha (Univ. of Arizona)

Poster Session 7: Wed, Oct 20 @ 10:00-10:45

Quantum Algorithms for Monte Carlo Integration using Pseudo-random Numbers
Koichi Miyamoto (Osaka Univ.)
Optimal Linear Optical Discrimination of Bell-like States
Dov Fields (Hunter College), Janos Bergou, Mark Hillery (City Univ. of New York), Vladimir Malinovsky (Army Research Lab)

Poster Session 8: Wed, Oct 20 @ 12:15-13:00

Rebalancing Bike Sharing Systems under Uncertainty using Quantum Bayesian Networks
Ramkumar Harikrishnakumar, Sima Borujeni (Wichita State Univ.), Syed Farhan Ahmad (R. V College of Engineering), Saideep Nannapaneni (Wichita State Univ.)
Solving Sensor Placement Problem In Real Water Distribution Networks Using Adiabatic Quantum Computation
Federico Bianchi, Stefano Speziali, Andrea Marini, Lorenzo Menculini, Massimiliano Proietti (Idea-Re S.r.l.), Loris F. Termite (K-Digitale S.r.l.), Alberto Garinei, Marcello Marconi (Guglielmo Marconi Univ. & Idea-Re S.r.l.), Andrea Delogu (BlueGold S.r.l.)

Poster Session 9: Wed, Oct 20 @ 14:30-15:15

Strategies in Quantum Metrology for Precise Measurements
Arunava Majumder (Indian Institute of Techn. Kharagapur), Harshank Shrotriya, Leong-Chuan Kwek (Nat. Univ. of Singapore)
Quantifying Geometric Measure of Entanglement of Multi-qubit Graph States on the IBM’s Quantum Computer
Nataliia Susulovska , Khrystyna Gnatenko (Ivan Franko National Univ. of Lviv)

Poster Session 10: Thu, Oct 21 @ 10:00-10:45

Measurement of Ion Motion Caused by Laser-Induced Stray Charges on Microfabricated Ion Trap Chip Surfaces
Changhyun Jung, Woojun Lee, Junho Jeong, Taehyun Kim, Dong-Il Cho (Seoul National Univ.)
On-demand Creation of Quantum Emitters in Hexagonal Boron Nitride on Non-patterned Substrates
Xiaohui Xu, Zachariah Martin, Demid Sychev, Alexei Lagutchev, Yong Chen, Vladimir Shalaev, Alexandra Boltasseva (Purdue Univ.)

Poster Session 11: Thu, Oct 21 @ 12:15-13:00

A Modular Quantum Key Distribution Software Stack for Rapid Experimental Prototyping Omar Amer, Kevin Freyberg (Univ. of Connecticut), Vaibhav Garg (Comcast Cable), Walter Krawec (Univ. of Connecticut) A Polarization Diversity CV-QKD Detection Scheme for Channels with Strong Polarization Drift Daniel Pereira, Nuno Silva, Armando Pinto (Inst. De Telecomunicações)

Poster Session 12: Thu, Oct 21 @ 14:30-15:15

Experiments on Fraud Detection Use Case with QML and TDA Mapper
Satanik Mitra, Kameshwar Rao Jv (HCL Technologies)
Multi-qubit Size-hopping Deutsch-Jozsa Algorithm with Qubit Reordering for Secure Quantum Key Distribution
Rohit De (Del Norte High School), Raymond Moberly, Colton Beery, Jeremy Juybari (Faster Logic, LLC), Kyle Sundqvist (San Diego State Univ.)

Poster Session 13: Fri, Oct 22 @ 10:00-10:45

Graph State Distribution
Wenbo Xie (Purdue Univ.), Wenhan Dai, Don Towsley (Univ. of Massachusetts Amherst)
A Quantum Binary Classifier based on Cosine Similarity
Davide Pastorello, Enrico Blanzieri (Univ. of Trento)

Poster Session 14 Fri, Oct 22 @ 12:15-13:00

Trainable Discrete Feature Embeddings for Quantum Machine Learning
Napat Thumwanit, Chayaphol Lortaraprasert, Hiroshi Yano, Rudy Raymond
Discriminating Quantum States with Quantum Machine Learning
David Quiroga (Univ. de Antioquia), Prasanna Date, Raphael Pooser (Oak Ridge Natl. Lab)

Poster Session 15: Fri, Oct 22 @ 14:30-15:15

An Engineer's Brief Introduction to Microwave Quantum Optics
Malida Hecht, Antonio Cobarrubia, Kyle Sundqvist (San Diego State Univ.)
Developing SLH Theory for Use with Microwave Circuits
Antonio Cobarrubia, Kyle Sundqvist (San Diego State Univ.)


QCE21 Posters Abstracts


Poster Session 1: Mon, Oct 18 @ 10:00-10:45

Variational Quantum Algorithm for Eigenvalue Problems of a Class of Schrödinger-type Partial Differential Equations
Paula García-Molina, Javier Rodríguez-Mediavilla, Juan José García-Ripoll (Inst. De Física)

Abstract: In this work, we develop a variational quantum algorithm to solve partial differential equations (PDE’s) using a space-efficient variational ansatz that merges structured quantum circuits for coarse-graining with Fourier-based interpolation. We implement variational circuits to represent symmetrical smooth functions as the ansatz and combine them with classical optimizers that differ on the gradient calculation: no gradient, numerical gradient and analytic gradient. We apply this method to the computation of the ground state of the one-dimensional quantum harmonic oscillator and the transmon qubit. In idealized quantum computers, we show that the harmonic oscillator can be solved with an infidelity of order 10^{-5} with 3 qubits and the transmon qubit with an error of order 10^{-4} with 4 qubits. We find that these fidelities can be approached in real noisy quantum computers, either directly or through error mitigation techniques. However, we also find that the precision in the estimate of the eigenvalues is still sub-par with other classical methods, suggesting the need for better strategies in the optimization and the evaluation of the cost function itself.
Poster Session 1: Mon, Oct 18 @ 10:00-10:45

Detecting Energy Levels of Spin Systems on IBM's Quantum Computer by Evolution of Mean Value of Physical Quantity
Khrystyna Gnatenko (Ivan Franko National Univ. of Lviv), Hanna Laba (Lviv Polytechnic National Univ.), Volodymyr Tkachuk (Ivan Franko National Univ. of Lviv))

Abstract: Finding energy levels of a quantum system is an important problem that can be solved using quantum computers. We showed that transition energies of a quantum system are related with the evolution of mean value of a physical quantity. In particular case when the operator of a physical quantity anticommutes with the Hamiltonian of a system we found that studies of the evolution of the mean value of this physical quantity give a possibility to determine the energy levels of the system and their degeneracy. On the basis of the results the energy levels of spin systems were detected on IBM’s quantum computers \textrm{ibmq\_manila} and \textrm{ibmq\_melbourne}. It is worth noting that spin systems are one of the most suitable systems for modeling them on a quantum computer. We considered a spin in magnetic field, spin chain with Ising interaction, spin square-lattice with isotropic and spatially anisotropic Ising interactions. The results obtained on the quantum devices correspond to the analytical one. It is important to note that finding the maximal or the minimal energy of the Ising model on square lattice with spatially anisotropic interaction is not a trivial problem. Therefore, the proposed algorithm for obtaining the energy levels opens a possibility to achieve the quantum supremacy in solving this problem on many qubit quantum computers.

Poster Session 2: Mon, Oct 18 @ 12:15-13:00

Implementing the Simplex Method with Grover's Search
Adeline Jordon, Saasha Joshi, Prashanti Priya Angara (Univ. of Victoria)

Abstract: The Simplex Method, as proposed by George Dantzig in 1947, is a widely-used practical algorithm for solving Linear Programs (LPs), which are systems of linear inequalities headed by a single linear objective function. We examine the difficulty of implementing quantum subroutines outlined by Giacomo Nannicini in Fast quantum subroutines for the simplex method in Q#. In particular, we examine the subroutine FindColumn(A, B, epsilon) which selects a valid entering variable (if any) using quantum search and quantum phase estimation algorithms and where A is the constraint matrix, B is the basis and epsilon is optimality tolerance. We focus on the challenges presented by transforming the matrices and vectors given by an LP into quantum states and the preparation of the oracle. Classically, choosing an entering variable in an LP with $n$ optimization variables, m constraints, and at most dc non-zero entries per column requires O(dc^{0.7}m^{1.9}+m^{2+o(1)+dc*n}) time using the fastest known algorithm for sparse matrix multiplication. Nannicini claims that adding quantum subroutines results in Ô((1/epsilon) * kappa*d*sqrt(n)*(dc n+dm)) time, where Ô hides polylogarithmic factors. We discuss whether the theoretical running time eclipses the practical usage and implementation difficulty by implementing the algorithm and running it on small and simple example LPs using the simulators provided by Q#.

Poster Session 3: Mon, Oct 18 @ 14:30-15:15

Simulation of Continuous-Variable Quantum Systems with Tensor Network
Ryutaro Nagai (blueqat inc.), Takao Tomono (Toppan Inc.), Yuichiro Minato (blueqat inc.)

Abstract: Tensor network is known as a powerful method to simulate quantum computation on a classical computer. Recently, the random quantum circuit used in the demonstration of quantum supremacy by Sycamore quantum computer have been simulated with tensor network method. Compared to the application of tensor networks to Discrete-Variable (DV) quantum computation, there are very few examples of application of tensor network to Continuous-Variable (CV) quantum computation. Therefore, we applied a tensor network structure called Matrix Product States (MPS) to CV quantum computation. Tensor network is expected to be useful for simulating Gaussian Boson Sampling (GBS), which is a promised near-term application of photonic quantum system. We outline the performance of tensor network-based simulation of CV quantum computation in GBS.
Poster Session 3: Mon, Oct 18 @ 14:30-15:15

Optimistic Entanglement Purification with few Quantum Memories
Mohammad Mobayenjarihani (Univ. of Massachusetts Amherst), Gayane Vardoyan (Delft Univ. of Technology), Donald Towsley (Univ. of Massachusetts Amherst)

Abstract: Entanglement generation over large distances is a challenging task due to photon loss, which grows exponentially with link length. Moreover, EPR pair generation over noisy channels results in imperfect states. Thus, a link is associated with a success probability and an initial fidelity for successfully-generated entanglement. Over time, the fidelity decreases due to environmental noise. Entanglement purification is a way of probabilistically increasing state fidelity. Traditionally, purification protocols perform the following steps: generate two or more EPR pairs between two nodes, execute a series of quantum gates on both sides, and exchange results via classical messages. In this work, we propose a twist on the original entanglement pumping scheme, wherein a fixed number of purification steps are performed successively, before the classical information exchange. This modification introduces optimism to the overall procedure, such that classical communication is performed only at the end, to check the measurement results. The protocol is also optimistic about the success of generating an entangled pair and does not wait for heralding signals before attempting purification. We study the effect of being optimistic on fidelity and the waiting time to generate an entangled pair as a function of the distance between network nodes. We observe an improvement in both fidelity and expected waiting time. We also study the effect of the number of purification steps on fidelity and latency and observe that typically no more than 2-3 purification steps are needed when limited by the number of memories.

Poster Session 4: Tue, Oct 19 @ 10:00-10:45

qopt: An experiment-oriented Qubit Simulation and Quantum Optimal Control Package
Julian Teske, Hendrik Bluhm (Forschungszentrum Jülich GmbH)

Abstract: Realistic modelling of qubit systems including noise and constraints imposed by control hardware is required for performance prediction and control optimization of quantum processors. We introduce qopt, a software framework for simulating qubit dynamics and robust quantum optimal control considering common experimental situations. To this end, we model open and closed qubit systems with a focus on the simulation of realistic noise characteristics and experimental constraints. Specifically, the influence of noise can be calculated using Monte Carlo methods, effective master equations or with the efficient filter function formalism, which enables the investigation and mitigation of auto-correlated noise. In addition, limitations of control electronics including finite bandwidth effects can be considered. The calculation of gradients based on analytic results is implemented to facilitate the efficient optimization of control pulses. The software is published under an open source license, well-tested and features a detailed documentation.
Poster Session 4: Tue, Oct 19 @ 10:00-10:45

Open-source Multi-channel Smart Arbitrary Waveform Generators (SAWG) for Quantum Information Processing
David Allcock (Univ. of Oregon & NIST), Christopher Balance (Univ. of Oxford), Sébastien Bourdeauducq (M-Labs Ltd.), Joseph Britton (Army Research Lab.), Michał Gąska (Warsaw Univ. of Technology), Thomas Harty (Univ. of Oxford), Jakub Jarosiński (Warsaw Univ. of Technology), Robert Jördens (QUARTIQ GmbH), Grzegorz Kasprowicz (Warsaw Univ. of Technology), Norman Krackow (M-Labs Ltd.), Paweł Kulik (Warsaw Univ. of Technology), David Nadlinger (Univ. of Oxford), Dorota Nowicka, Krzysztof Późniak, Tomasz Przywózki (Warsaw Univ. of Technology), Daniel Slichter (QUARTIQ GmbH), Mikołaj Sowiński (Warsaw Univ. of Technology), Marius Weber, Weida Zhang (Univ. of Oxford)

Abstract: Trapping ions, performing qubit operations and quantum multi-qubit gates require complex pulse spectra on several frequency bands. The Smart Arbitrary Waveform Generators (SAWG) Sayma and Phaser are designed to trap control and generate the Short-time Fourier transform (STFT) pulses. They have quad channels of over 1.2 GS/s (Giga Samples per second) 16-bit DACs and hundreds of MS/s (Mega Samples per second) ADCs. These modules are dedicated to implementing qubit operations, both optically and electronically. The Sayma and Phaser modules are part of Sinara family – a modular, open-source measurement and control hardware ecosystem dedicated to quantum applications that require deterministic high-resolution timing. The hardware is controlled and managed by the ARTIQ open-source software platform, which provides nanosecond timing resolution and sub-microsecond latency via a high-level programming language. This poster presents the Sayma and the Phaser construction and obtained characteristics.

Poster Session 5: Tue, Oct 19 @ 12:15-13:00

Joint Parity-Time and Anti-Parity-Time-symmetric Qubits
Julia Cen, Avadh Saxena (Los Alamos National Lab)

Abstract: One of the greatest obstacles to building large-scale quantum computers is the sensitivity of qubits to noise from their environment. This can shorten quantum computers’ computational lifetime and lead to high error rates when carrying out calculations. A common way to mitigate this is by using quantum error correction, but this can be expensive in terms of qubit count. We suggest another approach, which is through incorporating non-Hermiticity with joint Parity-Time (PT) and anti-Parity-Time (APT) symmetries into our qubits. We consider a PT and APT-symmetric two-level system coupled to a bosonic bath and present how to compute the dynamics and properties for these models by utilizing a time-dependent Dyson map for density matrices. The result is that we find the decoherence function for the PT-symmetric and APT-symmetric qubits decays slower than the standard Hermitian qubit. The von Neumann entanglement entropy for the PT and APT-symmetric qubit also grows more slowly compared to the Hermitian qubit. Furthermore, we find that the corresponding variance and area of quantum Fisher information is much higher for PT and APT-symmetric qubits compared with the Hermitian qubit. All these results suggest that non-Hermitian PT and APT-symmetric qubits may be better suited for quantum computing and quantum information processing than conventional Hermitian qubits.
Poster Session 5: Tue, Oct 19 @ 12:15-13:00

On Generating a Probability Distribution Amenable to NISQ Using Modifications to Grover’s Algorithm
Sayantan Pramanik, M Girish Chandra (Tata Consultancy Services)

Abstract: Generating a specific probability distribution is a very important problem and exploiting the inherent randomness of quantum circuits is worth looking at. In this poster, efficient generation of certain forms of probability distributions is considered through the use of both quantum and classical computing. In particular, probability distribution of combinatorial optimisation problems over possible bitstrings using only two oracle calls, which is independent of the problem-size. Towards achieving this, we invoke the modifications to Grover’s Algorithm as follows: a suitable number of work and additional two ancilla qubits are chosen, and each of them is transformed by a Hadamard Gate. Then, a Controlled Phase Oracle which appends a phase proportional to the cost of the state followed by a Local Diffuser rather than the usual Grover global diffuser. The suggested combination of the Oracle and the Local Diffuser is applied only once followed by measurements for a number of shots and a classical post processing. The overall scheme can generate a probability distribution proportional to the cosine of the phase appended to each state. Since the phase itself can be defined based on a cost function, this distribution is not too restrictive. The poster systematically outlines the steps, captures relevant circuits, and depicts typical results. The simplicity and low-depth circuitry of the proposition makes it suitable for Noisy Intermediate Scale Quantum implementation.

Poster Session 6: Tue, Oct 19 @ 14:30-15:15

A Low-noise and Scalable FPGA-based Analog Signal Generator for Quantum Gas Experiments
David Pahl, Lukas Pahl, Enis Mustafa, Zhenning Liu, Philipp Fabritius, Jeffrey Mohan, Peter Clements, Abdulkadir Akin, Tilman Esslinger (ETH Zurich)

Abstract: Achieving high fidelity for the measurement and control of quantum experiments imposes strict requirements on the precision and stability of surrounding electronics. Controlling electronics from a central device is more challenging when they are distributed in a laboratory and require analog signals where effects like ground loops and radiative cross-talk can limit their performance. Here, we present our design to address these challenges with a flexible and scalable analog signal generator. Our design is based on a field-programmable gate array (FPGA) development board, a custom PCB hosting a digital-to-analog converter (DAC) with 20-bit precision at 1MSPS, and a custom breakout board. The FPGA development board accepts data from a master PC via TCP/IP where a user programs the waveform and sampling rate of each output channel and writes the data to on-board RAM. At runtime, the direct memory access (DMA) and Serial Peripheral Interface (SPI) modules inside the FPGA stream data to the custom DAC board via an Ethernet cable carrying the samples as differential signals along with the supply voltage. We designed the DAC board to be resistant to digital and analog noise by separating ground planes to prevent ground loops and by using high-precision and low-noise power supplies and voltage reference circuits. External trigger and clock inputs can be used to synchronize the DACs and multiple FPGAs. The time resolution and precision of our solution is optimized for experiments on quantum gases though it is flexible and can be adapted for many more applications.
Poster Session 6: Tue, Oct 19 @ 14:30-15:15

Optimal Control‐plane Policies for Distributed Quantum Computation in Quantum Networks
Matheus Guedes de Andrade, Wenhai Dai, Don Towsley (Univ. of Massachusetts Amherst), Saikat Guha (Univ. of Arizona)

Abstract: Distributed quantum computing is a promising application of quantum networks as it leverages the power of interconnected small quantum computers to perform generic quantum operations that cannot be tackled by single computers alone. The key question in distributed quantum computing using quantum networks is applying a quantum gate on qubits that are geographically separated. In this work, we propose an optimization framework to describe distributed control policies that implement a quantum circuit with gates acting on qubits located in distinct nodes. The distributed control operations throughout the quantum network can be described by a logical control plane quantum walk protocol. We then investigate the problem of assigning logical qubits in a circuit description to physical qubits in the network, with the objective of minimizing the amount of quantum control information exchanged between nodes. We present an integer programming formulation for the problem that determines both qubit assignment and network paths for the transmission of quantum control information. Our formulation restricts to circuits with 2-qubit controlled gates and highlights the difficulty of the problem in terms of complexity. Our formulation can be used to analyze the demand for network resources in terms of the number of channel uses with respect to node capacity and circuit width.

Poster Session 7: Wed, Oct 20 @ 10:00-10:45

Quantum Algorithms for Monte Carlo Integration using Pseudo-random Numbers
Koichi Miyamoto (Osaka Univ.)

Abstract: Quantum algorithms for Monte Carlo integration (QMCI), which are based on quantum amplitude estimation (QAE), provide quadratic speed-up compared with classical counterparts, and are therefore widely investigated, along with applications to industrial problems. In particular, problems in finance such as credit portfolio risk measurement are important targets, since financial institutions commonly take enormous time and resources for these computational tasks in daily business, and their quantum speed-up provides a large impact. However, when we apply QMCI to these problems, it can be problematic that, typically, they are extremely high-dimensional and require numerous random numbers (RNs) to calculate the integrand. This is because, in the original implementation of QMCI, where the superposition states encoding the probability distributions of the RNs are generated on different quantum registers, the required qubit number is proportional to the number of RNs, and therefore extremely large. Then, in this poster, we propose the implementation of QMCI using pseudo-random numbers (PRNs), which requires less qubits. In this way, we sequentially generate PRNs on one register, which leads to tremendous reduction of qubits. Moreover, we show that, when the integrand has the form such that contributions from different RNs are separable into different terms, we can also achieve time complexity reduction with respect to the number of dimensions by combining the nested QAE and use of PRNs.
Poster Session 7: Wed, Oct 20 @ 10:00-10:45

Optimal Linear Optical Discrimination of Bell-like States
Dov Fields (Hunter College), Janos Bergou, Mark Hillery (City Univ. of New York), Vladimir Malinovsky (Army Research Lab)

Abstract: One major challenge in utilizing linear optical setups for quantum computing, is the limited scope of operations that are able to be preformed. Achieving universal quantum computing using only linear optical components comes at the cost of either requiring an untenable number of ancillary photons or the acceptance of some probability of failure. Being able to understand and optimize general linear optical operations is both an important and challenging task. In this poster, our goal is to illustrate this problem as well as the optimal solution derived for Bell-like states.

Poster Session 8: Wed, Oct 20 @ 12:15-13:00

Rebalancing Bike Sharing Systems under Uncertainty using Quantum Bayesian Networks
Ramkumar Harikrishnakumar, Sima Borujeni (Wichita State Univ.), Syed Farhan Ahmad (R. V College of Engineering), Saideep Nannapaneni (Wichita State Univ.)

Abstract: Smart Mobility is the key component of Smart City initiative that are being explored throughout the world. The bike-sharing system (BSS) aims to provide an alternative mode of Smart Mobility transportation system, and it is being widely adopted in urban areas. The use of bikes for short-distance travel helps to reduce traffic congestion, reduce carbon emissions, and decrease the risk of overcrowding. Effective bike sharing system operations requires rebalancing analysis, which corresponds to transferral of bikes across various bike stations to ensure the supply meets expected demand. A critical part for a bike sharing system operations is the effective management of rebalancing vehicle carrier operations that ensures bikes are restored in each station to its target value during every pick-up and drop-off operations. In this work, we present potential applications of Quantum Bayesian networks, which are quantum-equivalent to classical Bayesian networks for probabilistic rebalancing cost prediction under uncertainty. In this preliminary work, we demonstrate the proposed approach using IBM-Qiskit and compared the results classically using Netica for a case study involving rebalancing across three bike stations.
Poster Session 8: Wed, Oct 20 @ 12:15-13:00

Solving Sensor Placement Problem In Real Water Distribution Networks Using Adiabatic Quantum Computation
Federico Bianchi, Stefano Speziali, Andrea Marini, Lorenzo Menculini, Massimiliano Proietti (Idea-Re S.r.l.), Loris F. Termite (K-Digitale S.r.l.), Alberto Garinei, Marcello Marconi (Guglielmo Marconi Univ. & Idea-Re S.r.l.), Andrea Delogu (BlueGold S.r.l.)

Abstract: Quantum annealing has emerged in the last few years as a promising quantum computing approach to solving largescale combinatorial optimization problems. We formulate the problem of correctly placing pressure sensors on a Water Distribution Network (WDN) as a combinatorial optimization problem in the form of a Quadratic Unconstrained Binary Optimization (QUBO) or Ising model. Optimal sensor placement is indeed key to detect and isolate fault events. We outline the QUBO and Ising formulations for the sensor placement problem starting from the network topology and few other features. We present a detailed procedure to solve the problem by minimizing its Hamiltonian using PyQUBO, an opensource Python Library. We then apply our methods to the case of a real Water Distribution Network. Both simulated annealing and a hybrid quantum-classical approach on a DWave machine are employed.

Poster Session 9: Wed, Oct 20 @ 14:30-15:15

Strategies in Quantum Metrology for Precise Measurements
Arunava Majumder (Indian Institute of Techn. Kharagapur), Harshank Shrotriya, Leong-Chuan Kwek (Nat. Univ. of Singapore)

Abstract: Quantum metrology overcomes standard precision limits and has the potential to play a key role in quantum sensing. Conventional bounds to measurement precision such as the shot-noise limit are not as fundamental as the Heisenberg limits and can be beaten with quantum strategies that employ ‘quantum tricks’ such as squeezing and entanglement. Bipartite entangled quantum states with positive partial transpose (PPT), are usually considered to be too weakly entangled for applications. In the very 1st paper related to the usefulness of PPT states in metrology, the respected authors provided a specific strategy, Entanglement assisted strategy(EAS), for a family of PPT states claiming to have the highest possible accuracy, obtained from convex optimization. However, we, in our article, provided a modified strategy named “sequential” Ancilla assisted strategy(SAAS). We, through detailed calculation and plots, showed It can outperform the previous strategy for the same family of PPT states and can be applied to any family of states. Further, we reiterate the fact that sequential strategies are completely distinct from the repetition of an experiment multiple times. If we add repetitions to the experiment the Quantum Fisher Information(QFI) scales linearly in the number of repetitions, the concept of having sequences in both “EAS” and Ancilla assisted strategy can quadratically increase the QFI in the number of sequences and thus can scale in total O(n^3)(n=number of sequences as well as repetitions) and provide a greater advantage in metrology and sensing e.g. in magnetometry, gravitational wave detection, etc. Furthermore, we investigate the role of noise.
Poster Session 9: Wed, Oct 20 @ 14:30-15:15

Quantifying Geometric Measure of Entanglement of Multi-qubit Graph States on the IBM’s Quantum Computer
Nataliia Susulovska , Khrystyna Gnatenko (Ivan Franko National Univ. of Lviv)

Abstract: Quantum entanglement gives rise to a range of non-classical effects, which are extensively exploited in quantum computing and quantum communication. Therefore, detection and quantification of entanglement as well as preparation of highly entangled quantum states remain the fundamental objectives in these fields. Much attention has been devoted to the studies of graph states, which play a role of a central resource in quantum error correction, quantum cryptography and practical quantum metrology in the presence of noise. We examine multi-qubit graph states generated by the action of controlled phase shift operators on a separable quantum state of a system, in which all the qubits are in arbitrary identical states. Analytical expression is obtained for the geometric measure of entanglement of a qubit with other qubits in graph states represented by arbitrary graphs. We conclude that this quantity depends on the degree of the vertex corresponding to the qubit, the absolute values of the parameter of the phase shift gate and the parameter of the initial state the gate is acting on. Moreover, the geometric measure of entanglement of certain types of graph states is quantified on the IBM’s quantum computer ibmq_athens based on the measurements of the mean spin. Namely, we consider states associated with the native connectivity of ibmq_athens, the claw and the complete graphs. Appropriate protocols are proposed to prepare these states on the quantum computer. The results of quantum computations verify our theoretical findings.

Poster Session 10: Thu, Oct 21 @ 10:00-10:45

Measurement of Ion Motion Caused by Laser-Induced Stray Charges on Microfabricated Ion Trap Chip Surfaces
Changhyun Jung, Woojun Lee, Junho Jeong, Taehyun Kim, Dong-Il Cho (Seoul National Univ.)

Abstract: Stray charges induced on ion trap surfaces can push trapped ions away from a pseudopotential null point. The stray charges on ion trap surfaces are mainly induced by laser scattering on dielectric surfaces. To date, studies for suppressing laser-induced stray charges have been actively conducted. However, no study has been directed towards determining where the laser-induced stray charges mainly occur. In this paper, stray charges are intentionally induced at various spots on a microfabricated ion trap chip using a laser, and the ion motion caused by the intentionally induced stray charges is measured. The stray charges are induced at one spot at once, and the magnitude of the ion motion is estimated by comparing the ion positions before and after laser irradiation. When the laser irradiates the loading slot edge, the ion moves approximately −4.8 μm in the axial direction. When the laser irradiates the dielectric surfaces between two electrodes, the ion moves approximately −0.6 μm. On the other hand, the movement of the ion is not observed when the laser irradiates the top surfaces of the electrodes.
Poster Session 10: Thu, Oct 21 @ 10:00-10:45

On-demand Creation of Quantum Emitters in Hexagonal Boron Nitride on Non-patterned Substrates
Xiaohui Xu, Zachariah Martin, Demid Sychev, Alexei Lagutchev, Yong Chen, Vladimir Shalaev, Alexandra Boltasseva (Purdue Univ.)

Abstract: Two-dimensional hexagonal boron nitride (hBN) that hosts bright room-temperature single-photon emitters (SPEs) is a promising material platform for quantum information applications such as quantum computing, quantum communication and so on. An important step towards the practical application of hBN is the on-demand, position-controlled generation of SPEs. Several strategies have been reported to achieve the deterministic creation of hBN SPEs. However, they either rely on a substrate nanopatterning procedure that is not compatible with integrated photonic devices or utilize a radiation source that might cause unpredictable damage to hBN and underlying substrates. Here, we report a radiation- and lithography-free route to deterministically activate hBN SPEs by nanoindentation with an atomic force microscope (AFM) tip. The method is applied to thin hBN flakes (less than 25 nm in thickness) on flat silicon-dioxide-silicon substrates that can be readily integrated into on-chip photonic devices. The achieved SPEs yields are above 30% by utilizing multiple indent sizes, and a maximum SPE yield of 36% is demonstrated for the indent size of around 400 nm. Emitters with more than one SPEs per indentation site are created for indent size around 700 nm with a yield of ~70%. Our results mark an important step towards the deterministic creation and integration of hBN SPEs with photonic and plasmonic on-chip devices.

Poster Session 11: Thu, Oct 21 @ 12:15-13:00

A Modular Quantum Key Distribution Software Stack for Rapid Experimental Prototyping
Omar Amer, Kevin Freyberg (Univ. of Connecticut), Vaibhav Garg (Comcast Cable), Walter Krawec (Univ. of Connecticut)

Abstract: Quantum Key Distribution (QKD) is a rapidly advancing field, yet there is often a divide between theory, experiment, and practice. One difficulty in evaluating novel QKD protocols is in the post-processing needed. We are reporting here on the current development of a modular QKD software stack researchers can use to evaluate the performance of new QKD protocols, either using real hardware or simulated. We are designing our system to be modular and extendable allowing for rapid prototyping of new systems.
Poster Session 11: Thu, Oct 21 @ 12:15-13:00

A Polarization Diversity CV-QKD Detection Scheme for Channels with Strong Polarization Drift Daniel Pereira, Nuno Silva, Armando Pinto (Inst. De Telecomunicações)

Abstract: Continuous-variable quantum key distribution (CVQKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users connected through a communication channel. However, polarization drift in standard optical fibres can pose a considerable impairment, as it will degrade the efficiency of the coherent detection scheme if not compensated. In this work, we present a novel receiver configuration for CV-QKD that allows for passive polarization drift compensation. The presented results show that our detection system can effectively compensate random polarization drift even in very adverse scenarios.

Poster Session 12: Thu, Oct 21 @ 14:30-15:15

Experiments on Fraud Detection Use Case with QML and TDA Mapper
Satanik Mitra, Kameshwar Rao Jv (HCL Technologies)

Abstract: In the era of online financial transactions, it is significant for the credit card firms to be equipped with capabilities to identify fraudulent credit card transactions. This work covers study and implementation of two approaches for developing a credit card fraud detection model. First one, with hybrid quantum neural networks. In recent times, Quantum Computers (QC) are making their footprints into AI/ML domain. Quantum neural networks (QNN) hybrid with classical neural net has been used in various tasks such as – natural language processing, image processing etc. The second approach is with Topological Data Analysis (TDA). Finding topological structure in the input data also become relevant from the perspective of noise reduction. The visualization capabilities of TDA can become an aid in classification of credit card fraud as well. TDA is implemented with mapper based method here. In hybrid QNN, we are covering a reference implementation of Xanadu’s StrawberryFields, where a classical network processes the input to be fed into a QNN model. Although technique wise these two approaches are drastically different, for the sake of generalization, we implement TDA and hybrid QML with a publicly available credit card fraud detection dataset. We tested with balanced fraud and genuine features and hybrid QML model provides accuracy of 89.5% with, whereas TDA mapper with our novel approach of classification provides an accuracy of 94%.
Poster Session 12: Thu, Oct 21 @ 14:30-15:15

Multi-qubit Size-hopping Deutsch-Jozsa Algorithm with Qubit Reordering for Secure Quantum Key Distribution
Rohit De (Del Norte High School), Raymond Moberly, Colton Beery, Jeremy Juybari (Faster Logic, LLC), Kyle Sundqvist (San Diego State Univ.)

Abstract: As a classic and quintessential quantum computing implementation, the Deustch-Jozsa (DJ) algorithm is taught in many courses pertaining to quantum information science and technology (QIST). We exploit the Deustch-Jozsa framework as an educational testbed, illustrating fundamental qubit concepts while identifying associated algorithmic challenges. In this work, we present a self-contained exploration which may be beneficial in educating the future quantum workforce. Quantum Key Distribution (QKD), an improvement over the classical Public Key Infrastructure (PKI), allows two parties, Alice and Bob, to share a secret key by leveraging the superposition and entanglement properties of qubits. These properties can be used to detect Eve, a man-in-the-middle (MITM) attacker. For QKD the DJ-packets, consisting of the input qubits and the target qubit for the DJ-algorithm, carry the secret information between Alice and Bob. Previous research from Nagata and Nakamura discovered in 2015 that the DJ-algorithm for QKD allows an attacker to successfully intercept and remain undetected. Improving upon the past research we increased the entropy of DJ-packets through: (i) size hopping (H), where the number of qubits in consecutive DJ-packets keeps on changing and (ii) reordering (R) the qubits within the DJ-packets. These concepts together illustrate the multiple scales where entropy may increase in a DJ-algorithm to make for a more robust QKD framework, and therefore significantly decrease Eve’s chance of success. The proof of concept of the new schemes is tested on Google’s Cirq quantum simulator, and detailed python simulation show that attacker’s interception success rate can be drastically reduced.

Poster Session 13: Fri, Oct 22 @ 10:00-10:45

Graph State Distribution
Wenbo Xie (Purdue Univ.), Wenhan Dai, Don Towsley (Univ. of Massachusetts Amherst)

Abstract: Graph States are a particular class of entangled quantum states. They play essential roles in distributed quantum computing and quantum communication. In both cases, graph states are usually used as resources for a specific set of quantum computers to share information. Therefore, distributing a graph state across a quantum network consisting of several nodes connected by EPR pairs is an important problem. Currently, we do not have an efficient method for generating EPR pairs on demand. Hence EPR pairs needed to distribute graph states are critical resources, and it is important to design distribution algorithms that reduce the need for such resources. Meignant et al. [1] presented the edge-decorated complete graph (EDCG) algorithm that uses n(n-1)/2 number of EPR pairs to distribute the given graph state, where n is the size of a quantum network. Fischer [2] proposed the Graph State Transfer (GST) algorithm with a better upper bound in terms of the number of EPR pairs consumed. However, GST assumes using the unbounded amount of memory at each node and preparing the entire graph state in a single network node. In this poster, we present an integer programming formulation that removes these two assumptions that GST makes. The model accounts for both the topology of the quantum network and memory constraints at each network node has into account. Meanwhile, we propose a greedy algorithm to solve the integer programming problem.
Poster Session 13: Fri, Oct 22 @ 10:00-10:45

A Quantum Binary Classifier based on Cosine Similarity
Davide Pastorello, Enrico Blanzieri (Univ. of Trento)

Abstract: This proposal introduces the quantum implementation of a binary classifier based on cosine similarity between data vectors. The proposed quantum algorithm presents time complexity that is logarithmic in the product of the training set cardinality and the dimension of the vectors. It is based just on a suitable state preparation like the retrieval from a QRAM, a SWAP test circuit (two Hadamard gates and one Fredkin gate), and a measurement process on a single qubit. Furthermore there is a simple implementation of the considered classifier on the IBM quantum processor ibmq_16_melbourne.

Poster Session 14 Fri, Oct 22 @ 12:15-13:00

Trainable Discrete Feature Embeddings for Quantum Machine Learning
Napat Thumwanit, Chayaphol Lortaraprasert, Hiroshi Yano, Rudy Raymond

Abstract: Quantum classifiers provide sophisticated embeddings of input data in Hilbert space promising quantum advantage. The advantage stems from quantum feature maps encoding the inputs into quantum states with variational quantum circuits. A recent work shows how to map discrete features with fewer quantum bits using Quantum Random Access Coding (QRAC), an important primitive to encode binary strings into quantum states. We propose a new method to embed discrete features with trainable quantum circuits by combining QRAC and a recently proposed strategy for training quantum feature map called quantum metric learning. We show that the proposed trainable embedding requires not only as few qubits as QRAC but also overcomes the limitations of QRAC to classify inputs whose classes are based on hard Boolean functions. We numerically demonstrate its use in variational quantum classifiers to achieve better performances in classifying real-world datasets, and thus its possibility to leverage near-term quantum computers for quantum machine learning.
Poster Session 14 Fri, Oct 22 @ 12:15-13:00

Discriminating Quantum States with Quantum Machine Learning
David Quiroga (Univ. de Antioquia), Prasanna Date, Raphael Pooser (Oak Ridge Natl. Lab)

Abstract: An important use-case for machine learning (ML) is that of determining readout results in quantum computers. In quantum computing (QC), classical ML models are currently being used to discriminate IQ (in-phase and quadrature) signal data to discriminate between quantum states, which is a fundamental QC operation. In this paper, we propose a quantum k-means (QKMeans) clustering technique to discriminate quantum states on the IBM Bogota quantum device, and compare its performance to the KMeans technique (its classical counterpart). We used both algorithms to perform a correlation analysis and probe cross-talk between couples of qubits on the device. We observed that QKMeans obtained test and training scores at par with the classical KMeans, and testing scores that were marginally lower than KMeans when the clusters weren’t visually separable. The training times for QKMeans were observed to be at par with an implementation of the KMeans that was not optimized. In this case, we concluded a weak correlation with a Pearson correlation coefficient of 0.2 on the (1, 2) and (2, 3) qubit couples. After analyzing the training scores, we also conclude that the 1 qubit has the worst performance at readout evidenced by the signal data not being visually separable and the low scores obtained on both clustering algorithms compared to the other qubits. Its poor performance is further verified by the calibration data showing a high readout error of 8,4%. This technique can be used to probe correlations present in readout of quantum circuits.

Poster Session 15: Fri, Oct 22 @ 14:30-15:15

An Engineer's Brief Introduction to Microwave Quantum Optics
Malida Hecht, Antonio Cobarrubia, Kyle Sundqvist (San Diego State Univ.)

Abstract: Classical microwave circuit theory is incomplete in that it is incapable of fully modeling some phenomena at the quantum level. Various theoretical frameworks can be employed to incorporate single-photon statistical effects in the treatment of microwave networks. Such methods include quantum input-output network (QION) theory and SLH theory. A synthesis of the quantum and classical circuit treatments requires a description of second quantization within classical microwave theory. In order to make these topics understandable to an electrical engineer, we demonstrate some underpinnings of quantum optics in terms of microwave engineering. For example, we relate traveling-wave phasors for transmission lines, such as voltage and current, to bosonic field operators. The second quantization and necessary components for a quantum treatment of microwave circuit theory are summarized in a table that maps microwave scattering parameters to bosonic operators in a transmission line. To illustrate the need for second quantization, we use the results of second quantization along with first principles of quantum input-output network theory to determine a state-space representation and a transfer function of a single port quantum network. The same results could be obtained from SLH theory, and this serves as a case study for applying microwave theory to open quantum systems. The results of this work could be used to treat NISQ and other superconducting hardware. Additionally, these results could be incorporated into an applied curriculum, assisting in the engineering education of the future quantum workforce.
Poster Session 15: Fri, Oct 22 @ 14:30-15:15

Developing SLH Theory for Use with Microwave Circuits
Antonio Cobarrubia, Kyle Sundqvist (San Diego State Univ.)

Abstract: Circuit modeling and simulation techniques are necessary to the development of advanced microwave architectures. In particular, microwave circuits used in the quantum regime can produce a variety of single-photon phenomena related to qubits such as unitary gate operations, quantum illumination, and quantum interferometry. However, classical microwave formalism is incomplete to sufficiently describe these systems at this level. Noisy environments, for instance, destroy internal quantum information at the single-photon level, which makes it difficult to reliably control a quantum state. A theoretical infrastructure to account for this problem has been well-established in quantum optics as quantum input-output network (QION) theory. In this work, we consider an extension to QION theory, called SLH theory, to expand quantum stochastic differential equations to multi-port networks. A mathematical object composed of a network’s scattering parameters (S), coupling vector (L), and internal energy (H), known as an SLH triple, can fully describe its dynamical evolution at the quantum level. We show how microwave components can be converted into an SLH framework that retains the mathematical formalism of classical S-parameter techniques at the quantum limit. This makes SLH theory applicable to many interdisciplinary subfields within physics and engineering. We describe how a dynamical circuit model with universal quantum multi-port networks can be devised within SLH formalism. This can be applied to microwave circuit designs in the quantum limit.