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arXiv · 0905.2072

Radio Frequency Response of the Strongly Interacting Fermi Gases at Finite Temperatures

S. Y. Chang
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Abstract

The radio frequency spectrum of the fermions in the unitary limit at finite temperatures is characterized by the sum rule relations. We consider a simple picture where the atoms are removed by radio frequency excitations from the strongly interacting states into a state of negligible interaction. We calculate the moments of the response function in the range of temperature $0.08 \epsilon_F < T < 0.8 \epsilon_F$ using auxiliary field Monte Carlo technique (AFMC) in which continuum auxiliary fields with a density dependent shift are used. We estimate the effects of superfluid pairing from the clock shift. We find a qualitative agreement with the pairing gap - pseudogap transition behavior. We also find within the quasiparticle picture that in order for the gap to come into quantitative agreement with the previously known value at T=0, the effective mass has to be $m^* \sim 1.43 m$. Finally, we discuss implications for the adiabatic sweep of the resonant magnetic field.

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S. Y. Chang. 2009-05-13. Radio Frequency Response of the Strongly Interacting Fermi Gases at Finite Temperatures. https://doi.org/10.1103/physreva.80.033623

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