Complex scaling flows in quench dynamics of interacting particles

Abstract

Many-body systems driven out of equilibrium can exhibit scaling flows of the quantum state. For a sudden quench to resonant interactions between particles we construct a new class of analytical scaling solutions for the time evolved wave function with a complex scale parameter. These solutions determine the exact dynamical scaling of observables such as the pair correlation function, the contact and the fidelity. We give explicit examples of the nonequilibrium dynamics for two trapped fermions or bosons quenched to unitarity, for ideal Bose polarons, and for resonantly interacting, Borromean three-body systems. These solutions reveal universal scaling properties of interacting many-body systems that arise from the buildup of correlations at short times after the quench.

Universal Dynamic Scaling and Contact Dynamics in Quenched Quantum Gases

“…Given its simple operation in experiments, it becomes one of the most studied nonequilibrium dynamics, especially in ultracold atomic gases [1][2][3][4][5][6]. The advance in experiments further prompts extensive theoretical studies [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. For instance, the Cambridge group observed several universal phenomena in a Bose gas quenched from noninteracting to unitarity, such as the exponential form of the momentum distribution [3].…”