Qubit Reduction and Quantum Speedup for Wireless Channel Assignment Problem

In this article, we propose a novel method of formulating an NP-hard wireless channel assignment problem as a higher-order unconstrained binary optimization (HUBO), where the Grover adaptive search (GAS) is used to provide a quadratic speedup for solving the problem. The conventional method relies on a one-hot encoding of the channel indices, resulting in a […]

Testing Platform-Independent Quantum Error Mitigation on Noisy Quantum Computers

We apply quantum error mitigation (QEM) techniques to a variety of benchmark problems and quantum computers to evaluate the performance of QEM in practice. To do so, we define an empirically motivated, resource-normalized metric of the improvement of error mitigation, which we call the improvement factor, and calculate this metric for each experiment we perform. […]

A Modular Quantum Compilation Framework for Distributed Quantum Computing

For most practical applications, quantum algorithms require large resources in terms of qubit number, much larger than those available with current noisy intermediate-scale quantum processors. With the network and communication functionalities provided by the quantum Internet, distributed quantum computing (DQC) is considered as a scalable approach for increasing the number of available qubits for computational […]

Machine-Learning-Based Qubit Allocation for Error Reduction in Quantum Circuits

Quantum computing is a quickly growing field with great potential for future technology. Quantum computers in the current noisy intermediate-scale quantum (NISQ) era face two major limitations:1) qubit count and 2) error vulnerability. Although quantum error correction methods exist, they are not applicable to the current size of computers, requiring thousands of qubits, while current […]

Enabling Efficient Real-Time Calibration on Cloud Quantum Machines

Noisy intermediate-scale quantum computers are widely used for quantum computing (QC) from quantum cloud providers. Among them, superconducting quantum computers, with their high scalability and mature processing technology based on traditional silicon-based chips, have become the preferred solution for most commercial companies and research institutions to develop QC. However, superconducting quantum computers suffer from fluctuation […]

Quantum Topology Optimization via Quantum Annealing

We present a quantum annealing-based solution method for topology optimization (TO). In particular, we consider TO in a more general setting, i.e., applied to structures of continuum domains where designs are represented as distributed functions, referred to as continuum TO problems. According to the problem’s properties and structure, we formulate appropriate subproblems that can be […]

Design and Analysis of Digital Communication Within an SoC-Based Control System for Trapped-Ion Quantum Computing

Large-scale quantum information processing requires the use of quantum error-correcting codes to mitigate the effects of noise in quantum devices. Topological error-correcting codes, such as surface codes, are promising candidates, as they can be implemented using only local interactions in a 2-D array of physical qubits. Procedures, such as defect braiding and lattice surgery, can […]

Hardness of Braided Quantum Circuit Optimization in the Surface Code

Large-scale quantum information processing requires the use of quantum error-correcting codes to mitigate the effects of noise in quantum devices. Topological error-correcting codes, such as surface codes, are promising candidates, as they can be implemented using only local interactions in a 2-D array of physical qubits. Procedures, such as defect braiding and lattice surgery, can […]

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 […]