Quasi-Two-Dimensional Superfluid Fermionic Gases

We study a quasi-two-dimensional superfluid Fermi gas where the confinement in the third direction is due to a strong harmonic trapping. We investigate the behavior of such a system when the chemical potential is varied and find strong modifications of the superfluid properties due to the discrete harmonic oscillator states. We show that such quasi-two-dimensional behavior can be created and observed with current experimental capabilities.

Figure 1

Order parameter $\Delta (z)$ at $z=0$ as a function of dimensionless temperature $\tilde{T}=k_{B}T/\hslash {\omega }_z$ and chemical potential. We assumed a dimensionless coupling strength $g=-0.25$ here and in Fig. 2.

Figure 2

The lowest Andreev state single particle energy (dashed line), peak position of the RF spectrum (dotted-dashed line), and $\Delta (z=0)$ (solid line) as a function of chemical potential at $T=0$. The inset shows the peak position when the final state in the RF spectroscopy is initially empty, while in the main figure equal chemical potentials of the initial and final state were assumed.