Phase diagram and BCS-Bose condensation crossover in 1D and 2D Hubbard models

CCUR > College of Natural Science and Engineering > College of Science > Department of Physics > journal articles > Item 987654321/3004

Please use this identifier to cite or link to this item: https://irlib.pccu.edu.tw/handle/987654321/3004

Title:	Phase diagram and BCS-Bose condensation crossover in 1D and 2D Hubbard models
Authors:	Kocharian AN Yang C Chiang YL
Contributors:	物理系
Keywords:	Hubbard model Bethe-ansatz quantum Monte-Carlo BCS-BC crossover
Date:	2001
Issue Date:	2009-12-11 11:11:21 (UTC+8)
Abstract:	The ground-state energy, the concentration of double occupied sites and the density of bound electron pairs in low-dimensional attractive Hubbard model are calculated by means of the generalized self-consistent field (GSCF) approach. This approach gives an excellent agreement with the corresponding Bethe-ansatz solution and the quantum Monte-Carlo calculations in a wide range of interaction strength U < 0 and electron concentration n. A simple relationship is found between the order parameter and the density of bound electron pairs, valid for any dimension and in entire parameter space U, n and magnetic field h. The electron pairing and the crossover from the itinerant BCS regime into the Bose condensation regime of local pairs are studied in dependence of both U and n. The GSCF theory correctly displays the separation of the energy gap from the BCS order parameter at n not equal 1 as \U \ increases. (C) 2001 Elsevier Science B.V. All rights reserved.
Relation:	PHYSICA C Volume: 364 Pages: 131-133
Appears in Collections:	[Department of Physics ] journal articles

Files in This Item:

File	Description	Size	Format
index.html		0Kb	Text	544	View/Open