Nonequilibrium aspects of impurities in 1d quantum systems

Alvise Bastianello (Technical University of Munich)

Particles moving on a line are forced to scatter among themselves and with obstacles, enhancing the effect of interactions. In this talk, I will discuss some nonequilibrium aspects of extended quantum many-body systems in the presence of an impurity, in the form of a localized deformation of the Hamiltonian. In particular, I will focus on two different scenarios. In the first part, I will consider lattice systems, thus having a maximum velocity of excitations due to the Lieb-Robinson bound, in the presence of an impurity moving with constant velocity and discuss how the system reacts to subluminal and superluminal impurities. In the second part, I will discuss thermalization aspects of interacting impurities in an otherwise non-interacting system: can the impurity trigger thermalization, spreading thermally-distributed particles in the system? As I will discuss, the answer to this question is negative.

References:

Part A: A Bastianello, A De Luca, PRL 120 (6), 060602 (2018) A Bastianello, A De Luca, PRB 98 (6), 064304 (2018) A De Luca, A Bastianello, PRB 101 (8), 085139 (2020)

Part B: A Bastianello, EPL 125 (2), 20001 (2019) G Del Vecchio Del Vecchio, A De Luca, A Bastianello, SciPost Physics 12 (2), 060 (2022)