Open Access Archives - Page 12 of 15 - IEEE Transactions on Quantum Engineering

Encoding of Nonbinary Entanglement-Unassisted and Assisted Stabilizer Codes

January 12, 2021Priya J. Nadkarni; Shayan Srinivasa GaraniOpen Access, Quantum InformationComputer architecture, Encoding, Generators, Quantum entanglement, Quantum state, Quantum system, Tensors

Quantum coding schemes over qudits using preshared entanglement between the encoder and decoder can provide better error correction capability than without it. In this article, we develop procedures for constructing encoding operators for entanglement-unassisted and entanglement-assisted qudit stabilizer codes over Fpk, with p prime and k≥1 from first principles, generalizing prior works on qubit-based codes and codes that work […]

Benchmarking Hamiltonian Noise in the D-Wave Quantum Annealer

January 11, 2021Tristan Zaborniak; Rogério de SousaOpen Access, Quantum InformationAnnealing, Benchmark testing, Correlation, Logic gates, Qubit, Stationary state, Time measurement

Various sources of noise limit the performance of quantum computers by altering qubit states in an uncontrolled manner throughout computations and reducing their coherence time. In quantum annealers, this noise introduces additional fluctuations to the parameters defining the original problem Hamiltonian, such that they find the ground states of problems perturbed from those originally programmed. […]

Formulating and Solving Routing Problems on Quantum Computers

January 6, 2021Stuart Harwood; Claudio Gambella; Dimitar Trenev; Andrea Simonetto; David Bernal; Donny GreenbergOpen Access, Quantum Computer Architecture, Quantum InformationComputers, Mathematical model, Optimization, Quantum algorithm, Quantum computing, Routing, Vehicle routing

The determination of vehicle routes fulfilling connectivity, time, and operational constraints is a well-studied combinatorial optimization problem. The NP-hard complexity of vehicle routing problems has fostered the adoption of tailored exact approaches, matheuristics, and metaheuristics on classical computing devices. The ongoing evolution of quantum computing hardware and the recent advances of quantum algorithms (i.e., VQE, […]

Josephson Microwave Sources Applied to Quantum Information Systems

December 18, 2020Adam J. Sirois, Manuel A. Castellanos-Beltran, Anna E. Fox, Samuel P. Benz, Peter F. HopkinsOpen AccessFrequency measurement, Frequency synthesizers, Junctions, Microwave circuits, Quantum computing, Qubit, Temperature measurement

Quantum computers with thousands or millions of qubits will require a scalable solution for qubit control and readout electronics. Colocating these electronics at millikelvin temperatures has been proposed and demonstrated, but there exist significant challenges with power dissipation, reproducibility, fidelity, and scalability. In this article, we experimentally demonstrate the use of a Josephson arbitrary waveform […]

Finding Small and Large k-Clique Instances on a Quantum Computer

December 18, 2020Sara Ayman Metwalli; François Le Gall; Rodney Van MeterOpen Access, Quantum Computer Architecture, Quantum InformationComputers, Hamming weight, Hilbert space, Logic gates, Quantum computing, Qubit, Time complexity

Algorithms for triangle finding, the smallest nontrivial instance of the k -clique problem, have been proposed for quantum computers. Still, those algorithms assume the use of fixed access time quantum RAM. In this article, we present a practical gate-based approach to both the triangle-finding problem and its NP-hard k -clique generalization. We examine both constant factors for near-term implementation […]

Protocols for Creating and Distilling Multipartite GHZ States With Bell Pairs

December 11, 2020Sebastian de Bone; Runsheng Ouyang; Kenneth Goodenough; David ElkoussOpen Access, Quantum InformationDistributed quantum computation, entanglement distillation, Greenberger–Horne–Zeilinger (GHZ) states

The distribution of high-quality Greenberger-Horne-Zeilinger (GHZ) states is at the heart of many quantum communication tasks, ranging from extending the baseline of telescopes to secret sharing. They also play an important role in error-correction architectures for distributed quantum computation, where Bell pairs can be leveraged to create an entangled network of quantum computers. We investigate […]

High-Fidelity Control of Superconducting Qubits Using Direct Microwave Synthesis in Higher Nyquist Zones

December 8, 2020William D. Kalfus; Diana F. Lee; Guilhem J. Ribeill; Spencer D. Fallek; Andrew Wagner; Brian DonoOpen AccessBandwidth, Hardware, Instruments, Logic gates, Qubit, Radio frequency, Superconducting microwave devices

Control electronics for superconducting quantum processors have strict requirements for accurate command of the sensitive quantum states of their qubits. Hinging on the purity of ultra-phase-stable oscillators to upconvert very-low-noise baseband pulses, conventional control systems can become prohibitively complex and expensive when scaling to larger quantum devices, especially as high sampling rates become desirable for […]

Preparing Dicke States on a Quantum Computer

December 1, 2020Chandra Sekhar Mukherjee; Subhamoy Maitra; Vineet Gaurav; Dibyendu RoyOpen Access, Quantum Computer Architecture, Quantum InformationComputer architecture, Logic gates, Matrix decomposition, Noise measurement, Qubit, Task analysis, Tutorials

Exact requirement of controlled NOT (CNOT) and single-qubit gates to implement a quantum algorithm in a given architecture is one of the central problems in this computational paradigm. In this article, we take a tutorial approach in explaining the preparation of Dicke states (|D k n 〉) using concise realizations of partially defined unitary transformations. We show how […]

Quantum Attacks on HCTR and Its Variants

November 30, 2020Mostafizar Rahman; Goutam PaulOpen Access, Quantum InformationApproximation algorithms, Computational modeling, Cryptography, Encryption, Licenses, Registers, Search problems

Recently, in Asiacrypt 2019, Bonnetain et al. have shown attacks by quantum adversaries on FX construction and Even-Mansour Cipher without using superposition queries to the encryption oracle. In this article, we use a similar approach to mount new attacks on Hash-Counter (HCTR) and Hash-Counter-Hash (HCH) constructions. In addition, we mount attacks on HCTR, tweakable-HCTR, and […]

O(N^3) Measurement Cost for Variational Quantum Eigensolver on Molecular Hamiltonians

November 4, 2020Pranav Gokhale; Olivia Angiuli; Yongshan Ding; Kaiwen Gui; Teague Tomesh; Martin Suchara; Margaret MartonosiOpen AccessEnergy measurement, Extraterrestrial measurements, Qubit, Rotation measurement, Standards, Stationary state

Variational quantum eigensolver (VQE) is a promising algorithm for near-term quantum machines. It can be used to estimate the ground state energy of a molecule by performing separate measurements of O(N 4 ) terms. This quartic scaling appears to be a significant obstacle to practical applications. However, we note that it empirically reduces to O(N 3 ) when we […]