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arXiv · 1412.3203

BCS-BEC Crossover in Two-Dimensional Attractive Hubbard Model under Magnetic Field

Atsushi Tsuruta·Satoshi Hyodo·Kazumasa Miyake
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Abstract

The Bardeen-Cooper-Schrieffer (BCS)-Bose-Einstein condensation (BEC) crossover in the two-dimensional attractive Hubbard model under the magnetic field is discussed at the half-filling at T=0 K on the basis of the formalism of Eagles and Leggett. It is shown that the so-called Fulde-Ferrel-Larkin-Ovchinikov-like state with a non-zero center-of-mass wave vector ${\bf q}\not=0$ is not stabilized in the weak-coupling (BCS) region, while such a state with ${\bf q}\not=0$ is stabilized against that with ${\bf q}=0$ even in a wide strong-coupling (BEC) region where di-fermion molecules are formed. The physical implication of this surprising result is discussed.

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Atsushi Tsuruta, Satoshi Hyodo, Kazumasa Miyake. 2014-12-10. BCS-BEC Crossover in Two-Dimensional Attractive Hubbard Model under Magnetic Field. https://doi.org/10.7566/jpsj.83.063706

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