English
Related papers

Related papers: Hybrid quantum-classical approach for coupled-clus…

200 papers

The simulation of strongly correlated quantum impurity models is a significant challenge in modern condensed matter physics that has multiple important applications. Thus far, the most successful methods for approaching this challenge…

Strongly Correlated Electrons · Physics 2024-01-22 A. Erpenbeck , W. -T. Lin , T. Blommel , L. Zhang , S. Iskakov , L. Bernheimer , Y. Núñez-Fernández , G. Cohen , O. Parcollet , X. Waintal , E. Gull

We describe a simple formalism for generating classes of quantum circuits that are classically efficiently simulatable and show that the efficient simulation of Clifford circuits (Gottesman-Knill theorem) and of matchgate circuits…

Quantum Physics · Physics 2008-12-25 Richard Jozsa

A quantum transport model incorporating spin scattering processes is presented using the non-equilibrium Green's function (NEGF) formalism within the self-consistent Born approximation. This model offers a unified approach by capturing the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ahmet Ali Yanik , Gerhard Klimeck , Supriyo Datta

Quantum computing promises exponential improvements in solving large systems of partial differential equations (PDE), which forms a bottleneck in high-resolution computational fluid dynamics (CFD) simulations, in, among others, aerospace…

Quantum Physics · Physics 2025-10-22 Vladyslav Bohun , Andrij Kuzmak , Maciej Koch-Janusz

We simulate the nonequilibrium dynamics of two generic many-body quantum impurity models by employing the recently developed iterative influence-functional path integral method [Phys. Rev. B {\bf 82}, 205323 (2010)]. This general approach…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Dvira Segal , Andrew J. Millis , David R. Reichman

We introduce two kinds of quantum algorithms to explore microcanonical and canonical properties of many-body systems. The first one is a hybrid quantum algorithm that, given an efficiently preparable state, computes expectation values in a…

Quantum Physics · Physics 2021-05-19 Sirui Lu , Mari Carmen Bañuls , J. Ignacio Cirac

In the noisy intermediate-scale quantum (NISQ) era, flexible quantum operations are essential for advancing large-scale quantum computing, as they enable shorter circuits that mitigate decoherence and reduce gate errors. However, the…

The generating function of a Hamiltonian $H$ is defined as $F(t)=\langle e^{-itH}\rangle$, where $t$ is the time and where the expectation value is taken on a given initial quantum state. This function gives access to the different moments…

Quantum Physics · Physics 2021-11-29 Edgar Andres Ruiz Guzman , Denis Lacroix

We present a hybrid quantum-classical Green's function Monte Carlo (GFMC) algorithm for estimating the excited states of the nuclear shell model. The conventional GFMC method, widely used to find the ground state of a quantum many-body…

Quantum Physics · Physics 2025-08-25 Yongdan Yang , Ruyu Yang , Xiaosi Xu

Many applications of Green's functions (GFs) require their evaluation over intervals or at multiple points, motivating quantum algorithms that return an efficiently computable functional representation rather than mere point estimates. We…

Quantum Physics · Physics 2026-05-25 Jacob S. Nelson , Andrew B. Baczewski

Quantum-classical hybrid algorithms are emerging as promising candidates for near-term practical applications of quantum information processors in a wide variety of fields ranging from chemistry to physics and materials science. We report…

Models of quantum computation are important because they change the physical requirements for achieving universal quantum computation (QC). For example, one-way QC requires the preparation of an entangled "cluster" state followed by…

Quantum Physics · Physics 2010-09-28 Dave Bacon , Steven T. Flammia

Classical simulations of quantum systems are notoriously difficult computational problems, with conventional state vector and tensor network methods restricted to quantum systems that feature only a small number of qudits. The recently…

Quantum Physics · Physics 2026-01-28 Ben Harper , Azar C. Nakhl , Thomas Quella , Martin Sevior , Muhammad Usman

A unitary coupled-cluster (UCC) form for the wavefunction in the variational quantum eigensolver has been suggested as a systematic way to go beyond the mean-field approximation and include electron correlation in solving quantum chemistry…

Quantum Physics · Physics 2018-09-12 Ilya G. Ryabinkin , Tzu-Ching Yen , Scott N. Genin , Artur F. Izmaylov

In the molecular quantum chemistry community, coupled-cluster (CC) methods are well-recognized for their systematic convergence and reliability. The extension of the theory to extended systems has been comparably recent, so that…

Chemical Physics · Physics 2024-10-31 Andreas Grüneis , Evgeny Moerman , Matthias Scheffler , Tonghao Shen , Igor Ying Zhang

The determination of ground state properties of quantum systems is a fundamental problem in physics and chemistry, and is considered a key application of quantum computers. A common approach is to prepare a trial ground state on the quantum…

Quantum Physics · Physics 2023-12-13 Harish J. Vallury , Lloyd C. L. Hollenberg

The two-time Green function method in quantum electrodynamics of high-Z few-electron atoms is described in detail. This method provides a simple procedure for deriving formulas for the energy shift of a single level and for the energies and…

Atomic Physics · Physics 2009-11-06 V. M. Shabaev

Self-consistent approaches to superfluid many-fermion systems in 3-dimensions (and subsequent time-dependent approaches) require a large number of diagonalizations of very large dimension hermitian matrices, which results in enormous…

Nuclear Theory · Physics 2017-04-12 Shi Jin , Aurel Bulgac , Kenneth Roche , Gabriel Wlazłowski

We introduce a versatile method for preparing a quantum state whose amplitudes are given by some known function. Unlike existing approaches, our method does not require handcrafted reversible arithmetic circuits, or quantum table reads, to…

Quantum Physics · Physics 2025-07-10 Sam McArdle , András Gilyén , Mario Berta

A new method is proposed for determining the ground state wave function of a quantum many-body system on a quantum computer, without requiring an initial trial wave function that has good overlap with the true ground state. The technique of…

Quantum Physics · Physics 2017-09-26 David B. Kaplan , Natalie Klco , Alessandro Roggero