122 citations · 588 across the 19 of their papers we have counts for
19 papers
A comprehensive survey on quantum computer usage: How many qubits are employed for what purposes?
Tsubasa Ichikawa, Hideaki Hakoshima, Koji Inui +18
Quantum computers (QCs), which work based on the law of quantum mechanics, are expected to be faster than classical computers in several computational tasks such as prime factoring…
Quantum-Selected Configuration Interaction: classical diagonalization of Hamiltonians in subspaces selected by quantum computers
Keita Kanno, Masaya Kohda, Ryosuke Imai +4
We propose quantum-selected configuration interaction (QSCI), a class of hybrid quantum-classical algorithms for calculating the ground- and excited-state energies of many-electron…
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)…
Hunting for quantum-classical crossover in condensed matter problems
Nobuyuki Yoshioka, Tsuyoshi Okubo, Yasunari Suzuki +2
The intensive pursuit for quantum advantage in terms of computational complexity has further led to a modernized crucial question: {\it When and how will quantum computers outperfo…
Perturbation theory with quantum signal processing
Kosuke Mitarai, Kiichiro Toyoizumi, Wataru Mizukami
Perturbation theory is an important technique for reducing computational cost and providing physical insights in simulating quantum systems with classical computers. Here, we provi…
Solvent distribution effects on quantum chemical calculations with quantum computers
Yuichiro Yoshida, Wataru Mizukami, Norio Yoshida
We present a combination of three-dimensional reference interaction site model self-consistent field (3D-RISM-SCF) theory and the variational quantum eigensolver (VQE) to consider…
Constructing Local Bases for a Deep Variational Quantum Eigensolver for Molecular Systems
Luca Erhart, Kosuke Mitarai, Wataru Mizukami +1
Current quantum computers are limited in the number of qubits and coherence time, constraining the algorithms executable with sufficient fidelity. The variational quantum eigensolv…
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…
Hybrid quantum-classical algorithm for computing imaginary-time correlation functions
Rihito Sakurai, Wataru Mizukami, Hiroshi Shinaoka
Quantitative descriptions of strongly correlated materials pose a considerable challenge in condensed matter physics and chemistry. A promising approach to address this problem is…
Quantifying fermionic nonlinearity of quantum circuits
Shigeo Hakkaku, Yuichiro Tashima, Kosuke Mitarai +2
Variational quantum algorithms (VQAs) have been proposed as one of the most promising approaches to demonstrate quantum advantage on noisy intermediate-scale quantum (NISQ) devices…
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,…
Universal noise-precision relations in variational quantum algorithms
Kosuke Ito, Wataru Mizukami, Keisuke Fujii
Variational quantum algorithms (VQAs) are expected to become a practical application of near-term noisy quantum computers. Although the effect of the noise crucially determines whe…
Quadratic Clifford expansion for efficient benchmarking and initialization of variational quantum algorithms
Kosuke Mitarai, Yasunari Suzuki, Wataru Mizukami +2
Variational quantum algorithms are considered to be appealing applications of near-term quantum computers. However, it has been unclear whether they can outperform classical algori…
Solving Quasiparticle Band Spectra of Real Solids using Neural-Network Quantum States
Nobuyuki Yoshioka, Wataru Mizukami, Franco Nori
Establishing a predictive ab initio method for solid systems is one of the fundamental goals in condensed matter physics and computational materials science. The central challenge…
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…
Deep Variational Quantum Eigensolver: a divide-and-conquer method for solving a larger problem with smaller size quantum computers
Keisuke Fujii, Kaoru Mizuta, Hiroshi Ueda +3
We propose a divide-and-conquer method for the quantum-classical hybrid algorithm to solve larger problems with small-scale quantum computers. Specifically, we concatenate a variat…
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…
Theory of analytical energy derivatives for the variational quantum eigensolver
Kosuke Mitarai, Yuya O. Nakagawa, Wataru Mizukami
The variational quantum eigensolver (VQE) and its variants, which is a method for finding eigenstates and eigenenergies of a given Hamiltonian, are appealing applications of near-t…
Relativistic Internally Contracted Multireference Electron Correlation Methods
Toru Shiozaki, Wataru Mizukami
We report internally contracted relativistic multireference configuration interaction (ic-MRCI), complete active space second-order perturbation (CASPT2), and strongly contracted n…