activity
20192026
most citedDemonstration of quantum volume 64 on a superconducting quantum computing system

51 citations · 106 across the 13 of their papers we have counts for

collaborators

18 papers

quant-ph2026

Sample-based Quantum Diagonalization via Density Matrix Renormalization Group

Yuto Sugimoto, Tomonori Shirakawa, Yukio Kawashima +2

We introduce SqDMRG, which combines sample-based quantum diagonalization (SQD) with the density matrix renormalization group (DMRG). SqDMRG expands the sampled determinant space in…

quant-ph2026

Quantum--classical break-even in electronic dynamics of macrocyclic molecules

Shu Kanno, Kenji Sugisaki, Takashi Imamichi +5

Here we demonstrate quantum--classical break-even for chemical dynamics applications, reaching useful accuracy with a quantum-hardware wall-clock time comparable to that estimated…

quant-ph2026

Point-group symmetry analysis of many-electron wavefunctions on a quantum computer

Rei Sakuma, Kenji Sugisaki, Shu Kanno +2

A point group is a set of spatial symmetry operations in molecular systems and is an indispensable tool for analyzing molecular orbitals and spectroscopy experiments in chemistry.…

quant-ph2026★ 1 cited

Crossing the 12,000-atom barrier with heterogeneous quantum-classical supercomputing: quantum chemistry of protein-ligand complexes

Kenneth M. Merz, Akhil Shajan, Danil Kaliakin +21

We develop a workflow decomposing a molecule into fragments via quantum embedding and simulating them with a heterogeneous quantum-classical (HQC) method. We sample fragment electr…

quant-ph2025

Closed-loop calculations of electronic structure on a quantum processor and a classical supercomputer at full scale

Tomonori Shirakawa, Javier Robledo-Moreno, Toshinari Itoko +18

Quantum computers must operate in concert with classical computers to deliver on the promise of quantum advantage for practical problems. To achieve that, it is important to unders…

quant-ph2025

Shift of quantum critical point of discrete time crystal on a noisy quantum simulator

Yuta Hirasaki, Toshinari Itoko, Naoki Kanazawa +1

Recent advances in quantum technology have enabled the simulation of quantum many-body systems on real quantum devices. However, such quantum simulators are inherently subject to d…

quant-ph2025

Multilevel Circuit Optimization in Quantum Compilers: A Case Study

Tamiya Onodera, Yuki Sato, Toshinari Itoko +1

In this paper, we explore multilevel circuit optimization (MLCO), where we deploy multiple gate sets and progressively lower the source circuit through the gate sets to the target…

quant-ph2025★ 2 cited

Quantum Optimization Benchmarking Library - The Intractable Decathlon

Thorsten Koch, David E. Bernal Neira, Ying Chen +24

Through recent progress in hardware development, quantum computers have advanced to the point where benchmarking of (heuristic) quantum algorithms at scale is within reach. Particu…

quant-ph2024★ 21 cited

Hamiltonian simulation-based quantum-selected configuration interaction for large-scale electronic structure calculations with a quantum computer

Kenji Sugisaki, Shu Kanno, Toshinari Itoko +2

Quantum-selected configuration interaction (QSCI) is an approach for quantum chemical calculations using current quantum computers. In conventional QSCI, Slater determinants used f…

quant-ph2024★ 2 cited

Dynamics of measurement-induced state transitions in superconducting qubits

Yuta Hirasaki, Shunsuke Daimon, Naoki Kanazawa +3

We have investigated temporal fluctuation of superconducting qubits via the time-resolved measurement for an IBM Quantum system. We found that the qubit error rate abruptly changes…

quant-ph2024

Robust Error Accumulation Suppression for Quantum Circuits

Tatsuki Odake, Philip Taranto, Nobuyuki Yoshioka +4

We present a \textit{robust error accumulation suppression} (\textbf{REAS}) technique to manage errors in quantum computers. Our method reduces the accumulation of errors in any qu…

quant-ph2023★ 1 cited

Three-qubit Parity Gate via Simultaneous Cross Resonance Drives

Toshinari Itoko, Moein Malekakhlagh, Naoki Kanazawa +1

Native multi-qubit parity gates have various potential quantum computing applications, such as entanglement creation, logical state encoding and parity measurement in quantum error…

quant-ph2023★ 10 cited

Detection of temporal fluctuation in superconducting qubits for quantum error mitigation

Yuta Hirasaki, Shunsuke Daimon, Toshinari Itoko +2

We have investigated instability of a superconducting quantum computer by continuously monitoring the qubit output. We found that qubits exhibit a step-like change in the error rat…

quant-ph2021★ 12 cited

Approximate Solutions of Combinatorial Problems via Quantum Relaxations

Bryce Fuller, Charles Hadfield, Jennifer R. Glick +8

Combinatorial problems are formulated to find optimal designs within a fixed set of constraints. They are commonly found across diverse engineering and scientific domains. Understa…

quant-ph2021

Sampling Strategy Optimization for Randomized Benchmarking

Toshinari Itoko, Rudy Raymond

Randomized benchmarking (RB) is a widely used method for estimating the average fidelity of gates implemented on a quantum computing device. The stochastic error of the average gat…

quant-ph2020

Scheduling of Operations in Quantum Compiler

Toshinari Itoko, Takashi Imamichi

When scheduling quantum operations, a shorter overall execution time of the resulting schedule yields a better throughput and higher fidelity output. In this paper, we demonstrate…

quant-ph2020★ 51 cited

Demonstration of quantum volume 64 on a superconducting quantum computing system

Petar Jurcevic, Ali Javadi-Abhari, Lev S. Bishop +28

We improve the quality of quantum circuits on superconducting quantum computing systems, as measured by the quantum volume, with a combination of dynamical decoupling, compiler opt…

quant-ph2019★ 6 cited

Optimization of Quantum Circuit Mapping using Gate Transformation and Commutation

Toshinari Itoko, Rudy Raymond, Takashi Imamichi +1

This paper addresses quantum circuit mapping for Noisy Intermediate-Scale Quantum (NISQ) computers. Since NISQ computers constraint two-qubit operations on limited couplings, an in…