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arXiv · 0806.1747

Exact quantum Monte Carlo study of one dimensional trapped fermions with attractive contact interactions

Michele Casula·D. M. Ceperley·Erich J. Mueller
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Abstract

Using exact continuous quantum Monte Carlo techniques, we study the zero and finite temperature properties of a system of harmonically trapped one dimensional spin 1/2 fermions with short range interactions. Motivated by experimental searches for modulated Fulde-Ferrel-Larkin-Ovchinikov states, we systematically examine the impact of a spin imbalance on the density profiles. We quantify the accuracy of the Thomas-Fermi approximation, finding that for sufficiently large particle numbers (N > 100) it quantitatively reproduces most features of the exact density profile. The Thomas-Fermi approximation fails to capture small Friedel-like spin and density oscillations and overestimates the size of the fully paired region in the outer shell of the trap. Based on our results, we suggest a range of experimentally tunable parameters to maximize the visibility of the double shell structure of the system and the Fulde-Ferrel-Larkin-Ovchinikov state in the one dimensional harmonic trap. Furthermore, we analyze the fingerprints of the attractive contact interactions in the features of the momentum and pair momentum distributions.

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Michele Casula, D. M. Ceperley, Erich J. Mueller. 2008-06-10. Exact quantum Monte Carlo study of one dimensional trapped fermions with attractive contact interactions. https://doi.org/10.1103/physreva.78.033607

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