Towards Joule Expansion and Spin Transport of Fermi Gases in a Mutli-region Trap

An optical trap divided into multiple regions by programmable optical potentials provides a versatile platform for experiments on quantum gases out of equilibrium. We experimentally demonstrate the preparation of non-equilibrium initial states using a programmable potential controlled by a digital micromirror device (DMD), and propose protocols for Joule expansion and spin transport. Joule expansion in a unitary Fermi gas defines a well-posed problem in non-equilibrium dynamics, where the final state can be predicted from equilibrium thermodynamics, while the intermediate evolution provides a testbed for the dynamics of quantum fluids. We further present a protocol for the measurement of spin transport in a multi-region trap, showing how non-equilibrium spin and density distributions can be prepared using magnetic field gradients and light sheets, providing initial conditions for precise measurements of spin diffusivity and spin-heat coupling.