Journal article

Publication year: 2015

Pages: 86-93

Journal: Physics Letters B

Volume number: 742

ISSN: 0370-2693

eISSN: 1873-2445

Open access status: Gold

DOI Link: https://doi.org/10.1016/j.physletb.2015.01.014

Publisher: Elsevier

Abstract: 
We investigate the stability of the Sarma phase in two-component fermion systems in three spatial dimensions. For this purpose we compare strongly-correlated systems with either relativistic or non-relativistic dispersion relation: relativistic quarks and mesons at finite isospin density and spin-imbalanced ultracold Fermi gases. Using a Functional Renormalization Group approach, we resolve fluctuation effects onto the corresponding phase diagrams beyond the mean-field approximation. We find that fluctuations induce a second-order phase transition at zero temperature, and thus a Sarma phase, in the relativistic setup for large isospin chemical potential. This motivates the investigation of the cold atoms setup with comparable mean-field phase structure, where the Sarma phase could then be realized in experiment. However, for the non-relativistic system we find the stability region of the Sarma phase to be smaller than the one predicted from mean-field theory. It is limited to the BEC side of the phase diagram, and the unitary Fermi gas does not support a Sarma phase at zero temperature. Finally, we propose an ultracold quantum gas with four fermion species that has a good chance to realize a zero-temperature Sarma phase. (C) 2015 The Authors. Published by Elsevier B.V.

Harvard Citation style: Boettcher, I., Herbst, T., Pawlowski, J., Strodthoff, N., von Smekal, L. and Wetterich, C. (2015) Sarma phase in relativistic and non- relativistic systems, Physics Letters B, 742, pp. 86-93. https://doi.org/10.1016/j.physletb.2015.01.014

APA Citation style: Boettcher, I., Herbst, T., Pawlowski, J., Strodthoff, N., von Smekal, L., & Wetterich, C. (2015). Sarma phase in relativistic and non- relativistic systems. Physics Letters B. 742, 86-93. https://doi.org/10.1016/j.physletb.2015.01.014