Canonical BCS Approximation for the Attractive Hubbard Model

Details Canonical BCS Approximation for the Attractive Hubbard Model Canonical BCS Approximation for the Attractive Hubbard Model

1999-02-20

arxiv.org/abs/cond-mat/9902285v1

Physics

Condensed Matter

Superconductivity

4 pages, 3 figures, HTS99 conference proceeding

Scientific paper

10.1063/1.59610

We test the canonical BCS wave functions for fixed number of electrons for the attractive Hubbard model. We present results in one dimension for various chain lengths, electron densities, and coupling strengths. The ground-state energy and energy gap to the first excited state are compared with the exact solutions obtained by the Bethe ansatz as well as with the results from the conventional grand-canonical BCS approximations. While the canonical and grand-canonical BCS results are both in very good agreement with the exact results for the ground state energies, improvements due to conserving the electron number in finite systems are manifest in the energy gap. As the system size is increased, the canonical results converge to the grand-canonical ones. The ``parity'' effect that arises from the number parity (even or odd) of electrons are studied with our canonical scheme.

Affiliated with

Also associated with

No associations

Rating

Canonical BCS Approximation for the Attractive Hubbard Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Canonical BCS Approximation for the Attractive Hubbard Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Canonical BCS Approximation for the Attractive Hubbard Model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-95319