collaborators

7 papers

quant-ph2026

Nontrivial multi-product commutation relation toward reducing T-count in sequential Pauli-based computation

Yusei Mori, Hideaki Hakoshima, Keisuke Fujii

Quantum compilers that reduce the number of T gates are essential for minimizing the overhead of fault-tolerant quantum computation. Achieving further T-count reduction calls for i…

quant-ph2026

Polynomial time constructive decision algorithm for multivariable quantum signal processing

Yuki Ito, Hitomi Mori, Kazuki Sakamoto +1

Quantum signal processing (QSP) and quantum singular value transformation (QSVT) have provided a unified framework for understanding many quantum algorithms, including factorizatio…

quant-ph2026

On the quantum computational complexity of classical linear dynamics with geometrically local interactions: Dequantization and universality

Kazuki Sakamoto, Keisuke Fujii

The simulation of large-scale classical systems in exponentially small space on quantum computers has gained attention. The prior work demonstrated that a quantum algorithm offers…

quant-ph2025

Tensor Network Formulation of Dequantized Algorithms for Ground State Energy Estimation

Hidetaka Manabe, Takanori Sugimoto, Keisuke Fujii

Verifying quantum advantage for practical problems, particularly the ground state energy estimation (GSEE) problem, is one of the central challenges in quantum computing theory. Fo…

quant-ph2025

Out-of-Time-Order Correlator Spectroscopy

Keisuke Fujii

Out-of-time-order correlators (OTOCs) are central probes of quantum scrambling, and their generalizations have recently become key primitives for both benchmarking quantum advantag…

quant-ph2025

A Quantum Algorithm for Nonlinear Electromagnetic Fluid Dynamics via Koopman-von Neumann Linearization

Hayato Higuchi, Yuki Ito, Kazuki Sakamoto +2

To simulate plasma phenomena, large-scale computational resources have been employed in developing high-precision and high-resolution plasma simulations. One of the main obstacles…