Quantum Information Archives - Page 9 of 11 - 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, […]

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 […]

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 […]

Quantum Approximate Optimization With Parallelizable Gates

October 29, 2020Wolfgang LechnerOpen Access, Quantum Computer Architecture, Quantum InformationLattices, Logic gates, Optimization, Protocols, Qubit, Stationary state

The quantum approximate optimization algorithm (QAOA) has been introduced as a heuristic digital quantum computing scheme to find approximate solutions of combinatorial optimization problems. We present a scheme to parallelize this approach for arbitrary all-to-all connected problem graphs in a layout of quantum bits (qubits) with nearest-neighbor interactions. The protocol consists of single qubit operations […]

Voltage-Tunable Superconducting Resonators: A Platform for Random Access Quantum Memory

October 28, 2020Kasra Sardashti; Matthieu C. Dartiailh; Joseph Yuan; Sean Hart; Pat Gumann; Javad ShabaniOpen Access, Quantum InformationCouplings, Inductance, Logic gates, Qubit, Resonant frequency, Resonators, Superconducting microwave devices

In computing architectures, one important factor is the tradeoff between the need to couple bits of information (quantum or classical) to each other and to an external drive and the need to isolate them well enough in order to protect the information for an extended period of time. In the case of superconducting quantum circuits, […]

Multiblock ADMM Heuristics for Mixed-Binary Optimization on Classical and Quantum Computers

October 23, 2020Claudio Gambella; Andrea SimonettoOpen Access, Quantum Computer Architecture, Quantum InformationComputational modeling, Computers, Convergence, Convex functions, Noise measurement, Optimization, Quantum computing

Solving combinatorial optimization problems on current noisy quantum devices is currently being advocated for (and restricted to) binary polynomial optimization with equality constraints via quantum heuristic approaches. This is achieved using, for example, the variational quantum eigensolver (VQE) and the quantum approximate optimization algorithm (QAOA). In this article, we present a decomposition-based approach to extend […]