2011/05/22 by Kangjun Seo, Seo, Kangjun, Carlos A. R. Sá de Melo +1
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum, superfluid, helium dynamics #cond-mat.quant-gas
paper · pdf · doi:10.48550/arxiv.1105.4365
15 pages, 8 figures
arxiv created 2011/05/22 · arxiv updated 2011/05/24
We describe the relation between the isothermal atomic compressibility and density fluctuations in mixtures of two-component fermions with population or mass imbalance. We derive a generalized version of the fluctuation-dissipation theorem which is valid for both balanced and imbalanced Fermi-Fermi mixtures. Furthermore, we show that critical exponents for the compressibility can be extracted via an analysis of the density fluctuations when phase transitions occur as a function of population imbalance or interaction parameter. In addition, we demonstrate that in the presence of trapping potentials, the local compressibility, local spin-susceptibility and local density-density correlations can be extracted from experimental data via a generalized local fluctuation-dissipation theorem which is valid beyond the local density approximation. Lastly, we use the local density approximation to calculate theoretically the local compressibility, local spin-susceptibility and local density-density fluctuations to compare with experimental results as they become available.