Emergent Infrared Conformal Dynamics in Strongly Interacting Quantum Gases

Abstract

Conformal dynamics can appear in quantum gases when the interactions are fine tuned to be scale symmetric. One well-known example of such a system is a three-dimensional Fermi gas at a Feshbach resonance. In this letter, we illustrate how conformal dynamics can also emerge in the infrared limit in one-dimensional harmonically trapped Fermi gases, even though the system may not have exactly scale symmetric interactions. The conformal dynamics are induced by strong renormalization effects due to the nearby infrared stable scale invariant interaction. When the system approaches the infrared limit, or when the external harmonic trapping frequency $\omega_f \rightarrow 0$, the dynamics are characterized by a unique vanishingly small dissipation rate, $\Gamma \propto \omega_f$, rather than a constant as in generic interacting systems. We also examine the work done in a two-quench protocol, $W$, and the average power $\mathcal{P}$. In one dimension, the average power, $\mathcal{P} \propto \omega_f$, becomes vanishingly small in the infrared limit, a signature of emergent conformal dynamics.