International Conference on Low Temperature Physics (LT)

Collective Excitation Modes in a Dipolar and Non-Dipolar Fermi Gas Mixture

Takahiko Miyakawa, Eiji Nakano, Hiroyuki Yabu

Published May 22, 2023• 1 citation

Abstract

We investigate collective excitations in a dipolar and non-dipolar Fermi gas mixture at zero temperature.We obtain the density-density correlation functions of the mixtures in the ring diagram approximation.We analyze the dispersion relation determined by the poles of the density-density correlation functions and find two different types of collective modes: the undamped zero sound and the overdamped modes.We show that the undamped zero sound mode exists only at long wavelengths and the speed of undamped zero sound varies with the propagation direction due to an anisotropy of the dipolar interaction between dipolar fermions.We also show that the decay rate of the overdamped mode decreases as the inter-particle interaction strength between dipolar and non-dipolar fermions increases and the overdamped mode is replaced by unstable one if the inter-particle interaction strength is much strong.

DOI: 10.7566/jpscp.38.011014

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