The half-filled Hubbard chain in the Composite Operator Method: A comparison with Bethe Ansatz

Abstract

The one-dimensional Hubbard model at half-filling is studied in the framework of the Composite Operator Method using a static approximation. A solution characterized by strong antiferromagnetic correlations and a gap for any nonzero on-site interaction U is found. The corresponding ground-state energy, double occupancy and specific heat are in excellent agreement with those obtained within the Bethe Ansatz. These results show that the Composite Operator Method is an appropriate framework for the half-filled Hubbard chain and can be applied to evaluate properties, like the correlation functions, which cannot be obtained by means of the Bethe Ansatz, except for some limiting cases.

7 pages, 3 embedded Postscript figures, EuroTeX, submitted to EuroPhysics Letters

References in corpus (4)

• Spectral properties of the one-dimensional Hubbard model
• The Hubbard model in the two-pole approximation
• Incommensurate magnetism in cuprate materials
• Incommensurate spin fluctuations in the two-dimensional t-t'-U model

Cited by in corpus (8)

• The Hubbard model within the equations of motion approach
• Signatures of Spin and Charge Energy Scales in the Local Moment and Specific Heat of the Two-Dimensional Hubbard Model
• Bosonic sector of the two-dimensional Hubbard model studied within a two-pole approximation
• A Study of the Antiferromagnetic Phase in the Hubbard Model by means of the Composite Operator Method
• The Composite Operator Method (COM)
• Destruction of Superconductivity by Impurities in the Attractive Hubbard Model
• The Hubbard model with intersite interaction within the Composite Operator Method
• Symmetry Breaking in Occupation Number Based Slave-Particle Methods