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Diagonalization of full finite temperature Green's functions by quasi-particles

Peter A. Henning, Hiroomi Umezawa

arXiv:nucl-th/9304006Physics Letters BApr 1, 199314 citations

Quantum Dynamics at Finite Temperature

WORLD SCIENTIFIC eBooksJul 1, 19980 citations

Comment on Density of States of Tomonaga-Luttinger Model at Finite Temperatures

N. Nakamura, Yoshikazu Suzumura

By use of the single particle Green's function of the Tomonaga-Luttinger model at finite temperature, the density of states around the Fermi energy is calculated to examine the range of temperatures in which properties of the Luttinger liquid are found.

Progress of Theoretical PhysicsJan 1, 19975 citations

Green’s Functions of the Single-Particle Schrödinger Equation

John C. Inkson

Springer eBooksJan 1, 19840 citations

Green's Function Approach to the Bose-Hubbard Model

Matthias Ohliger, Axel Pelster

We use a diagrammatic hopping expansion to calculate finite-temperature Green functions of the Bose-Hubbard model which describes bosons in an optical lattice. This technique allows for a summation of subsets of diagrams, so the divergence of the Green function leads to non-perturbative results for the boundary between the superfluid and the Mott phase for finite temperatures. Whereas the first-order calculation reproduces the seminal mean-field result, the second order goes beyond and shifts the phase boundary in the immediate vicinity of the critical parameters determined by the latest high-precision Monte-Carlo simulations of the Bose-Hubbard model. In addition, our Green's function approach allows for calculating the excitation spectrum at finite temperature and for determining the effective masses of particles and holes.We use a diagrammatic hopping expansion to calculate finite-temperature Green functions of the Bose-Hubbard model which describes bosons in an optical lattice. This technique allows for a summation of subsets of diagrams, so the divergence of the Green function leads to non-perturbative results for the boundary between the superfluid and the Mott phase for finite temperatures. Whereas the first-order calculation reproduces the seminal mean-field result, the second order goes beyond and shifts the phase boundary in the immediate vicinity of the critical parameters determined by the latest high-precision Monte-Carlo simulations of the Bose-Hubbard model. In addition, our Green's function approach allows for calculating the excitation spectrum at finite temperature and for determining the effective masses of particles and holes.

arXiv:0810.4399Oct 24, 20082 citations

Green’s Function Approach to the Bose-Hubbard Model

Matthias Ohliger, Axel Pelster

We use a diagrammatic hopping expansion to calculate finite-temperature Green functions of the Bose-Hubbard model which describes bosons in an optical lattice. This technique allows for a summation of subsets of diagrams, so the divergence of the Green function leads to non-perturbative results for the boundary between the superfluid and the Mott phase for finite temperatures. Whereas the first-order calculation reproduces the seminal mean-field result, the second order goes beyond and shifts the phase boundary in the immediate vicinity of the critical parameters determined by high-precision Monte-Carlo simulations of the Bose-Hubbard model. In addition, our Green’s function approach allows for calculating the excitation spectrum both for zero and finite temperature and for determining the effective masses of particles and holes.We use a diagrammatic hopping expansion to calculate finite-temperature Green functions of the Bose-Hubbard model which describes bosons in an optical lattice. This technique allows for a summation of subsets of diagrams, so the divergence of the Green function leads to non-perturbative results for the boundary between the superfluid and the Mott phase for finite temperatures. Whereas the first-order calculation reproduces the seminal mean-field result, the second order goes beyond and shifts the phase boundary in the immediate vicinity of the critical parameters determined by high-precision Monte-Carlo simulations of the Bose-Hubbard model. In addition, our Green’s function approach allows for calculating the excitation spectrum both for zero and finite temperature and for determining the effective masses of particles and holes.

World Journal of Condensed Matter PhysicsJan 1, 201314 citations

Quantum Feedback Protocol for Calculating Single-Particle Green's Functions at Finite Temperature

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