Pauli Error Propagation-Based Gate Rescheduling for Quantum Circuit Error Mitigation

Noisy intermediate-scale quantum algorithms, which run on noisy quantum computers, should be carefully designed to boost the output state fidelity. While several compilation approaches have been proposed to minimize circuit errors, they often omit the detailed circuit structure information that does not affect the circuit depth or the gate count. In the presence of spatial […]

Depth Optimization of CZ, CNOT, and Clifford Circuits

We seek to develop better upper bound guarantees on the depth of quantum CZ gate, cnot gate, and Clifford circuits than those reported previously. We focus on the number of qubits n≤ 1 345 000 (de Brugière et al. , 2021), which represents the most practical use case. Our upper bound on the depth of CZ circuits is ⌊n/2+0.4993⋅log2(n)+3.0191⋅log(n)−10.9139⌋ , improving the best-known […]

Mutation Testing of Quantum Programs: A Case Study With Qiskit

As quantum computing is still in its infancy, there is an inherent lack of knowledge and technology to test a quantum program properly. In the classical realm, mutation testing has been successfully used to evaluate how well a program’s test suite detects seeded faults (i.e., mutants). In this article, building on the definition of syntactically […]

A Software Development Kit and Translation Layer for Executing Intel 8080 Assembler on a Quantum Computer (August 2022)

One of the major obstacles to the adoption of quantum computing is the requirement to define quantum circuits at the quantum gate level. Many programmers are familiar with high-level or low-level programming languages but not quantum gates nor the low-level quantum logic required to derive useful results from quantum computers. The steep learning curve involved […]

Efficient Construction of a Control Modular Adder on a Carry-Lookahead Adder Using Relative-Phase Toffoli Gates

Control modular addition is a core arithmetic function, and we must consider the computational cost for actual quantum computers to realize efficient implementation. To achieve a low computational cost in a control modular adder, we focus on minimizingKQ (where K is the number of logical qubits required by the algorithm, and Q is the elementary […]

Efficient Quantum State Preparation for the Cauchy Distribution Based on Piecewise Arithmetic

The benefits of the quantum Monte Carlo algorithm heavily rely on the efficiency of the superposition state preparation. So far, most reported Monte Carlo algorithms use the Grover–Rudolph state preparation method, which is suitable for efficiently integrable distribution functions. Consequently, most reported works are based on log-concave distributions, such as normal distributions. However, non-log-concave distributions […]

Grover on KATAN: Quantum Resource Estimation

This article presents the cost analysis of mounting Grover’s key search attack on the family of KATAN block cipher. Several designs of the reversible quantum circuit of KATAN are proposed. Owing to the National Insitute of Standards and Technology’s (NIST) proposal for postquantum cryptography standardization, the circuits are designed focusing on minimizing the overall depth. […]

A Grover Search-Based Algorithm for the List Coloring Problem

Graph coloring is a computationally difficult problem, and currently the best known classical algorithm for k -coloring of graphs on n vertices has runtimes Ω(2n) for k≥5 . The list coloring problem asks the following more general question: given a list of available colors for each vertex in a graph, does it admit a proper coloring? We propose a hybrid classical-quantum algorithm based […]

Layer VQE: A Variational Approach for Combinatorial Optimization on Noisy Quantum Computers

Combinatorial optimization on near-term quantum devices is a promising path to demonstrating quantum advantage. However, the capabilities of these devices are constrained by high noise or error rates. In this article, inspired by the variational quantum eigensolver (VQE), we propose an iterative layer VQE (L-VQE) approach. We present a large-scale numerical study, simulating circuits with […]

Topological-Graph Dependencies and Scaling Properties of a Heuristic Qubit-Assignment Algorithm

The qubit-mapping problem aims to assign and route qubits of a quantum circuit onto an noisy intermediate-scale quantum (NISQ) device in an optimized fashion, with respect to some cost function. Finding an optimal solution to this problem is known to scale exponentially in computational complexity; as such, it is imperative to investigate scalable qubit-mapping solutions […]