318 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- The University of OsakaJP16 papers
- Japan Science and Technology AgencyJP12 papers
- The University of TokyoJP7 papers
- Kyoto UniversityJP6 papers
- RIKENJP3 papers
- Mitsubishi Chemical (Japan)JP2 papers
- NTT (Japan)JP2 papers
- RIKEN Center for Quantum Computing2 papers
- Toyota Central Research and Development Laboratories (Japan)JP2 papers
- University of WaterlooCA2 papers
- Boston UniversityUS1 paper
- École Polytechnique Fédérale de LausanneCH1 paper
28 papers
Almost optimal measurement scheduling of molecular Hamiltonian via finite projective plane
Wataru Inoue, Koki Aoyama, Yusuke Teranishi +3
We propose an efficient and almost optimal scheme for measuring molecular Hamiltonians in quantum chemistry on quantum computers, which requires distinct measurements in the…
Averaging gate approximation error and performance of Unitary Coupled Cluster ansatz in Pre-FTQC Era
Kohdai Kuroiwa, Yuya O. Nakagawa
Fault-tolerant quantum computation (FTQC) is essential to implement quantum algorithms in a noise-resilient way, and thus to enjoy advantages of quantum computers even with presenc…
Density-Induced Hadron-Quark Crossover via the Formation of Cooper Triples
Hiroyuki Tajima, Shoichiro Tsutsui, Takahiro M. Doi +1
We discuss the hadron--quark crossover accompanied by the formation of Cooper triples (three-body counterpart of Cooper pairs) by analogy with the Bose--Einstein condensate to Bard…
Analytical formulation of the second-order derivative of energy for orbital-optimized variational quantum eigensolver: application to polarizability
Yuya O. Nakagawa, Jiabao Chen, Shotaro Sudo +2
We develop a quantum-classical hybrid algorithm to calculate the analytical second-order derivative of the energy for the orbital-optimized variational quantum eigensolver (OO-VQE)…
Local variational quantum compilation of a large-scale Hamiltonian dynamics
Kaoru Mizuta, Yuya O. Nakagawa, Kosuke Mitarai +1
Implementing time evolution operators on quantum circuits is important for quantum simulation. However, the standard way, Trotterization, requires a huge numbers of gates to achiev…
Quantum expectation-value estimation by computational basis sampling
Masaya Kohda, Ryosuke Imai, Keita Kanno +3
Measuring expectation values of observables is an essential ingredient in variational quantum algorithms. A practical obstacle is the necessity of a large number of measurements fo…
Non-adiabatic Quantum Wavepacket Dynamics Simulation Based on Electronic Structure Calculations using the Variational Quantum Eigensolver
Hirotoshi Hirai, Sho Koh
A non-adiabatic nuclear wavepacket dynamics simulation of the HO de-excitation process is performed based on electronic structure calculations using the variational quantum…
Molecular Structure Optimization based on Electrons-Nuclei Quantum Dynamics Computation
Hirotoshi Hirai, Takahiro Horiba, Soichi Shirai +4
A new concept of the molecular structure optimization method based on quantum dynamics computations is presented. Nuclei are treated as quantum mechanical particles, as are electro…
Non-normal Hamiltonian dynamics in quantum systems and its realization on quantum computers
Nobuyuki Okuma, Yuya O. Nakagawa
The eigenspectrum of a non-normal matrix, which does not commute with its Hermitian conjugate, is a central issue of non-Hermitian physics that has been extensively studied in the…
Analytical energy gradient for state-averaged orbital-optimized variational quantum eigensolvers and its application to a photochemical reaction
Keita Omiya, Yuya O. Nakagawa, Sho Koh +3
Elucidating photochemical reactions is vital to understand various biochemical phenomena and develop functional materials such as artificial photosynthesis and organic solar cells,…
Calculating the Green's function of two-site Fermionic Hubbard model in a photonic system
Jie Zhu, Yuya O. Nakagawa, Chuan-Feng Li +2
The Green's function has been an indispensable tool to study many-body systems that remain one of the biggest challenges in modern quantum physics for decades. The complicated calc…
Deep variational quantum eigensolver for excited states and its application to quantum chemistry calculation of periodic materials
Kaoru Mizuta, Mikiya Fujii, Shigeki Fujii +4
A programmable quantum device that has a large number of qubits without fault-tolerance has emerged recently. Variational Quantum Eigensolver (VQE) is one of the most promising way…
Variational quantum simulations of stochastic differential equations
Kenji Kubo, Yuya O. Nakagawa, Suguru Endo +1
Stochastic differential equations (SDEs), which models uncertain phenomena as the time evolution of random variables, are exploited in various fields of natural and social sciences…
Qulacs: a fast and versatile quantum circuit simulator for research purpose
Yasunari Suzuki, Yoshiaki Kawase, Yuya Masumura +17
To explore the possibilities of a near-term intermediate-scale quantum algorithm and long-term fault-tolerant quantum computing, a fast and versatile quantum circuit simulator is n…
Penalty methods for variational quantum eigensolver
Kohdai Kuroiwa, Yuya O. Nakagawa
The variational quantum eigensolver (VQE) is a promising algorithm to compute eigenstates and eigenenergies of a given quantum system that can be performed on a near-term quantum c…
Variational Quantum Simulation for Periodic Materials
Nobuyuki Yoshioka, Takeshi Sato, Yuya O. Nakagawa +2
We present a quantum-classical hybrid algorithm that simulates electronic structures of periodic systems such as ground states and quasiparticle band structures. By extending the u…
Optimal resource cost for error mitigation
Ryuji Takagi
One of the central problems for near-term quantum devices is to understand their ultimate potential and limitations. We address this problem in terms of quantum error mitigation by…
Calculating nonadiabatic couplings and Berry's phase by variational quantum eigensolvers
Shiro Tamiya, Sho Koh, Yuya O. Nakagawa
The variational quantum eigensolver (VQE) is an algorithm to find eigenenergies and eigenstates of systems in quantum chemistry and quantum many-body physics. The VQE is one of the…
Predicting excited states from ground state wavefunction by supervised quantum machine learning
Hiroki Kawai, Yuya O. Nakagawa
Excited states of molecules lie in the heart of photochemistry and chemical reactions. The recent development in quantum computational chemistry leads to inventions of a variety of…
Calculating transition amplitudes by variational quantum deflation
Yohei Ibe, Yuya O. Nakagawa, Nathan Earnest +4
Variational quantum eigensolver (VQE) is an appealing candidate for the application of near-term quantum computers. A technique introduced in [Higgot et al., Quantum 3, 156 (2019)]…
Experimental quantum kernel machine learning with nuclear spins in a solid
Takeru Kusumoto, Kosuke Mitarai, Keisuke Fujii +2
We employ so-called quantum kernel estimation to exploit complex quantum dynamics of solid-state nuclear magnetic resonance for machine learning. We propose to map an input to a fe…
Orbital optimized unitary coupled cluster theory for quantum computer
Wataru Mizukami, Kosuke Mitarai, Yuya O. Nakagawa +3
We propose an orbital optimized method for unitary coupled cluster theory (OO-UCC) within the variational quantum eigensolver (VQE) framework for quantum computers. OO-UCC variatio…
Calculation of the Green's function on near-term quantum computers
Suguru Endo, Iori Kurata, Yuya O. Nakagawa
The Green's function plays a crucial role when studying the nature of quantum many-body systems, especially strongly-correlated systems. Although the development of quantum compute…
Variational Quantum Algorithm for Non-equilibrium Steady States
Nobuyuki Yoshioka, Yuya O. Nakagawa, Kosuke Mitarai +1
We propose a quantum-classical hybrid algorithm to simulate the non-equilibrium steady state of an open quantum many-body system, named the dissipative-system Variational Quantum E…