JILA Science Seminar - Out-of-Equilibrium Quantum Field Dynamics in Coherently-Coupled Superfluid Mixtures

Giacomo Guarda / University of Trento

Out-of-Equilibrium Quantum Field Dynamics in Coherently-Coupled Superfluid Mixtures

 

Event Details / Abstract
A coherently-coupled superfluid mixture of sodium atoms can realize a ferromagnetic-like system supporting both first- and second-order quantum phase transitions, which enables the study of out-of-equilibrium field dynamics in an extended system. These transitions manifest in the local population imbalance, which acts as an effective magnetization. The first-order phase transition exhibits hysteresis properties, enabling the study of field metastability, also known as False Vacuum Decay. We prepare the system in a homogeneous metastable state and deterministically seed a bubble, i.e. a region locally in the ground state, allowing us to directly observe its evolution in real time. In parallel, the second-order paramagnetic-to-ferromagnetic phase transition allows us to probe the Kibble–Zurek mechanism, observing stochastic domain formation and defect density scaling with the quench rate.