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We construct a finite spin-1/2 chain model (quantum domino) interacting with a Fermi field, capable of emitting a scalar fermion from the last spin in the chain. The chain with dynamics gradually reversing the neighbouring spins emits…

Mathematical Physics · Physics 2012-12-11 Pavel Bóna , Michal Širaň

Lattice field theory is a useful tool for studying strongly interacting theories in condensed matter physics. A prominent example is the unitary Fermi gas: a two-component system of fermions interacting with divergent scattering length.…

Quantum Gases · Physics 2011-03-23 Olga Goulko , Matthew Wingate

A method to calculate the one-body Green's function for ground states of correlated electron materials is formulated by extending the variational Monte Carlo method. We benchmark against the exact diagonalization (ED) for the one- and…

Strongly Correlated Electrons · Physics 2020-11-11 Maxime Charlebois , Masatoshi Imada

We present an improved upper bound for the ground state energy of lattice fermion models with sign problem. The bound can be computed by numerical simulation of a recently proposed family of deformed Hamiltonians with no sign problem. For…

High Energy Physics - Lattice · Physics 2009-11-07 Matteo Beccaria

We give a bound on the ground state energy of a system of $N$ non-interacting fermions in a three dimensional cubic box interacting with an impurity particle via point interactions. We show that the change in energy compared to the system…

Mathematical Physics · Physics 2019-08-27 Thomas Moser , Robert Seiringer

By variational Monte-Carlo method developed Ceperley et al. for the simulation of fermi systems in macroscopic confining potential well we simulate various spin ground states of the coulomb clusters with 2,3 and 4 particles in a broad…

Condensed Matter · Physics 2007-05-23 B. Abdullaev , A. D. Kidisyuk , M. M. Musakhanov

The ground state parameters of the two-dimensional S=1/2 antiferromagnetic Heisenberg model are calculated using the Stochastic Series Expansion quantum Monte Carlo method for L*L lattices with L up to 16. The finite-size results for the…

Strongly Correlated Electrons · Physics 2008-12-18 A. W. Sandvik

We present a calculation by including the relativistic and off-shell contributions to the interaction potentials between two spin-1/2 fermions mediated by the exchange of light spin-0 particles, in both momentum and coordinate spaces. Our…

High Energy Physics - Phenomenology · Physics 2024-10-15 Yang Zhong , Zhi-Hui Guo , Hai-Qing Zhou

The calculation of the ground state and thermodynamics of mass-imbalanced Fermi systems is a challenging many-body problem. Even in one spatial dimension, analytic solutions are limited to special configurations and numerical progress with…

Quantum Gases · Physics 2018-07-20 Lukas Rammelmüller , William J. Porter , Joaquín E. Drut , Jens Braun

We use the coupled cluster method to high orders of approximation in order to calculate the ground-state energy, the ground-state magnetic order parameter, and the spin gap of the spin-1/2 J_1-J_2 model on the square lattice. We obtain…

Strongly Correlated Electrons · Physics 2015-01-16 J. Richter , R. Zinke , D. J. J. Farnell

We describe a path-integral ground-state quantum Monte Carlo method for light nuclei in continuous space. We show how to efficiently update and sample the paths with spin-isospin dependent and spin-orbit interactions. We apply the method to…

Nuclear Theory · Physics 2022-10-28 Rong Chen , Kevin E. Schmidt

We investigate Nagaoka ferromagnetism in the two-dimensional Hubbard model with one hole using the spin-adapted ($SU(2)$ conserving) full configuration interaction quantum Monte Carlo method. This methodology gives us access to the ground…

Strongly Correlated Electrons · Physics 2021-12-15 Sujun Yun , Werner Dobrautz , Hongjun Luo , Ali Alavi

A diffusion Monte Carlo algorithm is introduced that can determine the correct nodal structure of the wave function of a few-fermion system and its ground-state energy without an uncontrolled bias. This is achieved by confining signed…

Computational Physics · Physics 2020-02-05 Alexander A. Kunitsa , So Hirata

We simulated the 3-band Hubbard model using the Constrained Path Monte Carlo (CPMC) method in search for a possible superconducting ground state. The CPMC is a ground state method which is free of the exponential scaling of computing time…

Superconductivity · Physics 2016-08-31 M. Guerrero , J. E. Gubernatis , Shiwei Zhang

Motivated by the so-called cubical regime in magnon chiral perturbation theory, we propose a new method to calculate the low-energy constant, namely the spin-wave velocity $c$ of spin-1/2 antiferromagnets with $O(N)$ symmetry in a Monte…

Strongly Correlated Electrons · Physics 2015-05-20 F. -J. Jiang

We present two Diffusion Monte Carlo (DMC) algorithms for systems of ultracold quantum gases featuring synthetic spin-orbit interactions. The first one is a discrete spin generalization of the T- moves spin-orbit DMC, which provides an…

Quantum Gases · Physics 2018-12-05 J. Sanchez-Baena , J. Boronat , F. Mazzanti

We report quantum Monte Carlo calculations of superfluid Fermi gases with short-range two-body attractive interactions with infinite scattering length. The energy of such gases is estimated to be $(0.44 \pm 0.01)$ times that of the…

Atomic Physics · Physics 2009-11-10 J. Carlson , S. Y. Chang , V. R. Pandharipande , K. E. Schmidt

We probe the superconducting gap in the zero temperature ground state of an attractively interacting spin-imbalanced two-dimensional Fermi gas with Diffusion Monte Carlo. A condensate fraction at nonzero pair momentum evidences a spatially…

Strongly Correlated Electrons · Physics 2019-12-11 D. C. W. Foo , G. J. Conduit

Using effective field theory methods, we calculate for the first time the complete fourth-order term in the Fermi-momentum or $k_{\rm F} a_s$ expansion for the ground-state energy of a dilute Fermi gas. The convergence behavior of the…

Nuclear Theory · Physics 2020-02-05 C. Wellenhofer , C. Drischler , A. Schwenk

The kinetic energy is estimated for the ground-state of liquid $^3$He at equilibrium density. The obtained value for this quantity, $10.16\pm0.05$ K/atom at density $0.0163~\mbox{\AA}$, is in agreement with most of the experimental data…

Quantum Gases · Physics 2019-01-30 V. Zampronio , S. A. Vitiello