20 papers
An efficient quantum Hadamard product algorithm for functions
Xinchi Huang, Hirofumi Nishi, Tomofumi Zushi +1
We propose an efficient quantum algorithm for preparing the Hadamard product state of two quantum states whose amplitudes are generated by functions on a uniform grid with grid num…
End-to-End Molecular Dynamics with a Langevin Thermostat on Quantum Circuits
Masari Watanabe, Hirofumi Nishi, Taichi Kosugi +3
We construct a quantum-circuit framework for finite-temperature molecular dynamics in the canonical ensemble (NVT) with a Langevin thermostat, connecting canonical state preparatio…
Koopman--von Neumann Molecular Dynamics for Green--Kubo Transport Coefficients
Masari Watanabe, Hirofumi Nishi, Taichi Kosugi +3
We formulate the Green--Kubo transport coefficients of classical molecular dynamics as a readout problem for quantum algorithms using the Koopman--von Neumann (KvN) representation.…
Overcoming the Matrix-Product-State Encoding Barrier via DMRG-Guided Probabilistic Imaginary-Time Evolution
Masari Watanabe, Hirofumi Nishi, Taichi Kosugi +2
Ground-state preparation is a fundamental task in quantum simulation, because the overlap of the prepared state with the true ground state significantly affects the overall cost of…
Quantum algorithms for density functional theory with minimal readout
Yuansheng Zhao, Hirofumi Nishi, Taichi Kosugi +5
While quantum computers have shown significant promise for electronic structure calculations, their potential to accelerate density functional theory (DFT) calculations remains unc…
Channel-agnostic finite-temperature phase estimation averaged over variable grids: reconstruction of Green's function for dynamical mean-field theory
Taichi Kosugi, Hirofumi Nishi, Keito Kasebayashi +2
For treating correlated electronic systems on quantum computers, we propose a quantum-classical hybrid scheme for dynamical mean-field theory (DMFT). In the quantum part of the sch…