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The integral equation method is widely used in numerical simulations of 2D/3D acoustic and electromagnetic scattering problems, which needs a large number of values of the Green's functions. A significant topic is the scattering problems in…

Numerical Analysis · Mathematics 2018-07-26 Bo Zhang , Ruming Zhang

Inspired by the recent proposed Legendre orthogonal polynomial representation of imaginary-time Green's functions, we develop an alternate representation for the Green's functions of quantum impurity models and combine it with the…

Strongly Correlated Electrons · Physics 2016-12-08 Li Huang , Liang Du

A state-preserving quantum counting algorithm is used to obtain coefficients of a Lanczos recursion from a single ground state wavefunction on the quantum computer. This is used to compute the continued fraction representation of an…

Quantum Physics · Physics 2021-03-10 Thomas E. Baker

We propose a first-principles method of efficiently evaluating electron-transport properties of very long systems. Implementing the recursive Green's function method and the shifted conjugate gradient method in the transport simulator based…

Mesoscale and Nanoscale Physics · Physics 2021-01-20 Yoshiyuki Egami , Shigeru Tsukamoto , Tomoya Ono

The three key elements of a quantum simulation are state preparation, time evolution, and measurement. While the complexity scaling of time evolution and measurements are well known, many state preparation methods are strongly…

Quantum Physics · Physics 2022-03-24 Trevor Keen , Bo Peng , Karol Kowalski , Pavel Lougovski , Steven Johnston

We write the Green function of the $d$-dimensional hypercubic lattice in a piecewise form covering the entire real frequency axis. Each piece is a single integral involving modified Bessel functions of the first and second kinds. The…

Mathematical Physics · Physics 2012-10-23 Yen Lee Loh

Simulating time evolution of quantum systems is one of the most promising applications of quantum computing and also appears as a subroutine in many applications such as Green's function methods. In the current era of NISQ machines we…

Quantum Physics · Physics 2021-06-21 Nathan Fitzpatrick , Harriet Apel , David Muñoz Ramo

We show in detail how the Jordan-Wigner transformation can be used to simulate any fermionic many-body Hamiltonian on a quantum computer. We develop an algorithm based on appropriate qubit gates that takes a general fermionic Hamiltonian,…

Quantum Physics · Physics 2007-05-23 E. Ovrum , M. Hjorth-Jensen

It has been shown that the Schwinger-Dyson equations for non-Hermitian theories implicitly include the Hilbert-space metric. Approximate Green functions for such theories may thus be obtained, without having to evaluate the metric…

High Energy Physics - Theory · Physics 2015-05-18 H. F. Jones

Basing on the relation between the Coulomb Green function and the Green function of harmonic oscillator, the algebraic representation of the many-particle Coulomb Green function in the form of annihilation and creation operators is…

Quantum Physics · Physics 2007-05-23 Nguyen Hoang Quoc , Nguyen Ngoc Ty , Le Van Hoang , Nguyen Khac Nhap

The Green's function coupled cluster (GFCC) method is a powerful many-body tool for computing the electronic structure of molecular and periodic systems, especially when electrons of the system are strongly correlated. However, for the GFCC…

Computational Physics · Physics 2019-04-18 Bo Peng , Roel Van Beeumen , David B. Williams-Young , Karol Kowalski , Chao Yang

Compilation optimizes quantum algorithms performances on real-world quantum computers. To date, it is performed via classical optimization strategies. We introduce a class of quantum algorithms to perform compilation via quantum computers,…

Quantum Physics · Physics 2025-09-25 Davide Rattacaso , Daniel Jaschke , Marco Ballarin , Ilaria Siloi , Simone Montangero

We discuss an integral equation approach that enables fast computation of the response of nonlinear multi-degree-of-freedom mechanical systems under periodic and quasi-periodic external excitation. The kernel of this integral equation is a…

Dynamical Systems · Mathematics 2019-05-10 Shobhit Jain , Thomas Breunung , George Haller

Quantum computers offer the potential to efficiently simulate the dynamics of quantum systems, a task whose difficulty scales exponentially with system size on classical devices. To assess the potential for near-term quantum computers to…

Quantum Physics · Physics 2023-07-06 Nathan M. Myers , Ryan Scott , Kwon Park , Vito W. Scarola

Precise algorithms capable of providing controlled solutions in the presence of strong interactions are transforming the landscape of quantum many-body physics. Particularly exciting breakthroughs are enabling the computation of non-zero…

Solving the Anderson impurity model typically involves a two-step process, where one first calculates the ground state of the Hamiltonian, and then computes its dynamical properties to obtain the Green's function. Here we propose a hybrid…

Several widely used methods for the calculation of band structures and photo emission spectra, such as the GW approximation, rely on Many-Body Perturbation Theory. They can be obtained by iterating a set of functional differential equations…

Strongly Correlated Electrons · Physics 2012-01-31 Giovanna Lani , Pina Romaniello , Lucia Reining

The famous, yet unsolved, Fermi-Hubbard model for strongly-correlated electronic systems is a prominent target for quantum computers. However, accurately representing the Fermi-Hubbard ground state for large instances may be beyond the…

Quantum computers, using efficient Hamiltonian evolution routines, have the potential to simulate Green's functions of classically-intractable quantum systems. However, the decoherence errors of near-term quantum processors prohibit large…

Quantum Physics · Physics 2023-12-20 Diogo Cruz , Duarte Magano

Coupled cluster Green's function (GFCC) calculation has drawn much attention in the recent years for targeting the molecular and material electronic structure problems from a many body perspective in a systematically improvable way.…

Chemical Physics · Physics 2021-04-23 Bo Peng , Ajay Panyala , Karol Kowalski , Sriram Krishnamoorthy