Tunable instability and long-lived density modulations in hydrodynamic dipolar Fermi gases.

Recent experiments have demonstrated collisional shielding of heteronuclear molecules with microwave and DC electric fields, allowing stable hydrodynamic samples of ultracold polar molecular gases. Just as predicted and observed in the quantum degenerate regime, nondegenerate hydrodynamic gases can also experience collapse due to the attractive dipolar mean-field at large enough dipole moments. However, we find that this collapse is surpressed by kinetic and collisional effects, leading to the existence of a long-lived density modulated mode. We present the conditions required to achieve this long-lived mode, and their expected lifetimes due to thermal fluctuations.