Beyond Gaussian pair fluctuation theory for strongly interacting Fermi gases
arXiv:1602.07391 · doi:10.1103/PhysRevA.94.013610
Abstract
Interacting Fermi systems in the strongly correlated regime play a fundamental role in many areas of physics and are of particular interest to the condensed matter community. Though weakly inter- acting fermions are understood, strongly correlated fermions are difficult to describe theoretically as there is no small interaction parameter to expand about. Existing strong coupling theories rely heavily on the so-called many-body T-matrix approximation that sums ladder-type Feynman diagrams. Here, by acknowledging the fact that the effective interparticle interaction (i.e., the vertex function) becomes smaller above three dimensions, we propose an alternative way to reorganize Feynman diagrams and develop a theoretical framework for interacting Fermi gases beyond the ladder approximation. As an application, we solve the equation of state for three- and two-dimensional strongly interacting fermions and find excellent agreement with experimental [Science 335, 563 (2012)] and other theoretical results above the temperature 0.5TF .
6 pages, 4 figures
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Cited by in corpus (5)
- Pseudogaps in strongly interacting Fermi gases
- Breakdown of the Fermi polaron description near Fermi degeneracy at unitarity
- Collective modes of a two-dimensional Fermi gas at finite temperature
- Dynamic structure factor of a strongly correlated Fermi superfluid within a density functional theory approach
- Unitary Fermi superfluid near the critical temperature: thermodynamics and sound modes from elementary excitations