English
Related papers

Related papers: The Stochastic Green Function (SGF) algorithm

200 papers

Simulating noninteracting fermion systems is a common task in computational many-body physics. In absence of translational symmetries, modeling free fermions on $N$ modes usually requires poly$(N)$ computational resources. While often…

Quantum Physics · Physics 2026-02-24 Maarten Stroeks , Daan Lenterman , Barbara Terhal , Yaroslav Herasymenko

We propose a new Monte Carlo algorithm for the numerical study of general lattice models in Hamiltonian form. The algorithm is based on an initial Ansatz for the ground state wave function depending on a set of free parameters which are…

Statistical Mechanics · Physics 2009-10-31 Matteo Beccaria

In this paper, we present a powerful method (Atomistic Green's Function, AGF) for calculating the effective Hamiltonian of acoustic and elastic wave-scatterers. The ability to calculate the effective Hamiltonian allows for the study of…

Applied Physics · Physics 2024-04-30 Hossein Khodavirdi , Zhun-Yong Ong , Ankit Srivastava

We present a real-time second-order Green's function (GF) method for computing excited states in molecules and nanostructures, with a computational scaling of $O(N_{\rm e}^3$), where $N_{\rm e}$ is the number of electrons. The cubic scaling…

Chemical Physics · Physics 2024-01-29 Leopoldo Mejía , Jia Yin , David R. Reichman , Roi Baer , Chao Yang , Eran Rabani

We present a Hamiltonian Monte Carlo algorithm to sample from multivariate Gaussian distributions in which the target space is constrained by linear and quadratic inequalities or products thereof. The Hamiltonian equations of motion can be…

Computation · Statistics 2013-06-06 Ari Pakman , Liam Paninski

The q-Gaussian distribution results from maximizing certain generalizations of Shannon entropy under some constraints. The importance of q-Gaussian distributions stems from the fact that they exhibit power-law behavior, and also generalize…

Systems and Control · Computer Science 2013-11-12 Debarghya Ghoshdastidar , Ambedkar Dukkipati , Shalabh Bhatnagar

We compute the partition function of an anyon-like harmonic oscillator. The well known results for both the bosonic and fermionic oscillators are then reobtained as particular cases as ours. The technique we employ is a non-relativistic…

High Energy Physics - Theory · Physics 2009-10-28 H. Boschi-Filho , C. Farina , A. de Souza Dutra

We propose a scheme for the construction of one-particle Green's function (GF) of an interacting electronic system via statistical sampling on a quantum computer. Although the non-unitarity of creation and annihilation operators for the…

Quantum Physics · Physics 2020-02-19 Taichi Kosugi , Yu-ichiro Matsushita

As part of a systematic algorithm study, we present first results on a performance comparison between a multibosonic algorithm and the hybrid Monte Carlo algorithm as employed by the SESAM collaboration. The standard Wilson fermion action…

High Energy Physics - Lattice · Physics 2008-11-26 W. Schroers , N. Eicker , M. D'Elia , Ph. de Forcrand , C. Gebert , Th. Lippert , I. Montvay , B. Orth , M. Pepe , K. Schilling

The properties of interacting bosons in a weak, one-dimensional, and bichromatic optical with a rational ratio of the constituting wavelengths $\lambda_1$ and $\lambda_2$ are numerically examined along a broad range of the Lieb-Liniger…

Quantum Gases · Physics 2016-10-12 Asaad R. Sakhel

In this article we derive the lattice Green Functions (GFs) of graphene using a Tight Binding Hamiltonian incorporating both first and second nearest neighbour hoppings and allowing for a non-orthogonal electron wavefunction overlap. It is…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 James A. Lawlor , Mauro S. Ferreira

The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is…

High Energy Physics - Lattice · Physics 2008-11-26 M. A. Clark

Lattice Green's Functions (LGFs) are fundamental solutions to discretized linear operators, and as such they are a useful tool for solving discretized elliptic PDEs on domains that are unbounded in one or more directions. The majority of…

Numerical Analysis · Mathematics 2025-04-01 James Gabbard , Wim M. van Rees

In the framework of the hybrid quantum-classical variational cluster approach (VCA) to strongly correlated electron systems one of the goals of a quantum subroutine is to find single-particle correlation functions of lattice fermions in…

Quantum Physics · Physics 2025-06-26 Gino Bishop , Dmitry Bagrets , Frank K. Wilhelm

The boundary Green's function (bGF) approach has been established as a powerful theoretical technique for computing the transport properties of tunnel-coupled hybrid nanowire devices. Such nanowires may exhibit topologically nontrivial…

Mesoscale and Nanoscale Physics · Physics 2020-03-13 M. Alvarado , A. Iks , A. Zazunov , R. Egger , A. Levy Yeyati

In this paper we study stochastic quasi-Newton methods for nonconvex stochastic optimization, where we assume that noisy information about the gradients of the objective function is available via a stochastic first-order oracle (SFO). We…

Optimization and Control · Mathematics 2017-05-23 Xiao Wang , Shiqian Ma , Donald Goldfarb , Wei Liu

Filter methods realize a projection from a superposed quantum state onto a target state, which can be efficient if two states have sufficient overlap. Here we propose a quantum Gaussian filter (QGF) with the filter operator being a Gaussian…

Quantum Physics · Physics 2022-09-19 Min-Quan He , Dan-Bo Zhang , Z. D. Wang

We consider derivative-free black-box global optimization of expensive noisy functions, when most of the randomness in the objective is produced by a few influential scalar random inputs. We present a new Bayesian global optimization…

Machine Learning · Computer Science 2016-02-23 Saul Toscano-Palmerin , Peter I. Frazier

We generalize the Hamiltonian Monte Carlo algorithm with a stack of neural network layers and evaluate its ability to sample from different topologies in a two dimensional lattice gauge theory. We demonstrate that our model is able to…

High Energy Physics - Lattice · Physics 2021-05-10 Sam Foreman , Xiao-Yong Jin , James C. Osborn

Computation of the Green's function is crucial to study the properties of quantum many-body systems such as strongly correlated systems. Although the high-precision calculation of the Green's function is a notoriously challenging task on…