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arXiv · 1409.5070

Phase structure of spin-imbalanced unitary Fermi gases

I. Boettcher·J. Braun·T. K. Herbst·J. M. Pawlowski·D. Roscher·C. Wetterich
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Abstract

We investigate the phase structure of spin-imbalanced unitary Fermi gases beyond mean-field theory by means of the Functional Renormalization Group. In this approach, quantum and thermal fluctuations are resolved in a systematic manner. The discretization of the effective potential on a grid allows us to accurately account for both first- and second-order phase transitions that are present on the mean-field level. We compute the full phase diagram in the plane of temperature and spin-imbalance and discuss the existence of other conjectured phases such as the Sarma phase and a precondensation region. In addition, we explain on a qualitative level how we expect that in-situ density images are affected by our findings and which experimental signatures may potentially be used to probe the phase structure.

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I. Boettcher, J. Braun, T. K. Herbst, J. M. Pawlowski, D. Roscher, C. Wetterich. 2015-01-23. Phase structure of spin-imbalanced unitary Fermi gases. https://doi.org/10.1103/physreva.91.013610

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