Observation of a dynamical topological phase transition

Understand

Phase transitions are a fundamental concept in science describing diverse phenomena ranging from, e.g., the freezing of water to Bose-Einstein condensation.

• While the concept is well-established in equilibrium, similarly fundamental concepts for systems far from equilibrium are just being explored, such as the recently introduced dynamical phase transition (DPT).
• Here we report on the first observation of a DPT in the dynamics of a fermionic many-body state after a quench between two lattice Hamiltonians.
• With time-resolved state tomography in a system of ultracold atoms in optical lattices, we obtain full access to the evolution of the wave function.