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Density-Induced Breaking of Pairs in the Attractive Hubbard Model

Bumsoo Kyung·E. G. Klepfish·P. E. Kornilovitch
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Abstract

A conserving T-matrix approximation is applied to the two-dimensional attractive Hubbard model in the low-density regime. A set of self-consistent equations is solved in the real-frequency domain to avoid the analytic continuation procedure. By tuning the chemical potential the particle density was varied in the limits 0.01 < n < 0.18. For the value of the attractive potential U=8t the binding energy of pairs monotonically decreases with increasing n, from its zero-density limit 2.3t and vanishes at a critical density n=0.19. A pairing-induced pseudogap in the single-particle density of states is found at low densities and temperatures.

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Bumsoo Kyung, E. G. Klepfish, P. E. Kornilovitch. 1998-02-23. Density-Induced Breaking of Pairs in the Attractive Hubbard Model. https://doi.org/10.1103/physrevlett.80.3109

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