The 1D Hubbard model within the Composite Operator Method

Abstract

Although effective for two dimensional (2D) systems, some approximations may fail in describing the properties of one-dimensional (1D) models, which belong to a different universality class. In this paper, we analyze the adequacy of the Composite Operator Method (COM), which provides a good description of many features of 2D strongly correlated systems, in grasping the physics of 1D models. To this purpose, the 1D Hubbard model is studied within the framework of the COM by considering a two-pole approximation and a paramagnetic ground state. The local, thermodynamic and single-particle properties, the correlation functions and susceptibilities are calculated in the case of half filling and arbitrary filling. The results are compared with those obtained by the Bethe Ansatz (BA) as well as by other numerical and analytical techniques. The advantages and limitations of the method are analyzed in detail.

19 RevTeX pages, 41 embedded eps figures

Cited by in corpus (12)

• The Hubbard model within the equations of motion approach
• Underdoped cuprates phenomenology in the 2D Hubbard model within COM(SCBA)
• Emery vs. Hubbard model for cuprate superconductors: a Composite Operator Method study
• Bosonic sector of the two-dimensional Hubbard model studied within a two-pole approximation
• Composite Operator Method analysis of the underdoped cuprates puzzle
• The Hubbard model beyond the two-pole approximation: a Composite Operator Method study
• The Composite Operator Method (COM)
• The Hubbard model with intersite interaction within the Composite Operator Method
• Phase diagrams of half-filled 1D and 2D extended Hubbard model within COM
• The composite operator method route to the 2D Hubbard model and the cuprates
• Quasi-particle propagation across semiconductor-Mott insulator interfaces
• COM(3p) solution of the 2D Hubbard model: momentum resolved quantities