arXiv:1311.1926 · Physical Review B
Finite-time interaction quench in a Luttinger liquid
Rashi Sachdeva, Tanay Nag, Amit Agarwal, Amit Dutta
Abstract
We analyze the dynamics of a Luttinger model following a quench in the electron-electron interaction strength, where the change in the interaction strength occurs over a finite time scale $\ensuremath{\tau}$. We study the Loschmidt echo (the overlap between the initial and final state) as a function of time, both numerically and within a perturbation scheme, treating the change in the interaction strength as a small parameter, for all $\ensuremath{\tau}$. We derive the corrections appearing in (a) the Loschmidt echo for a finite quench duration $\ensuremath{\tau}$, (b) the scaling of the echo following a sudden $(\ensuremath{\tau}\ensuremath{\rightarrow}0)$ quench, and (c) the scaling of the echo after an adiabatic $(\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\infty})$ quench. We study in detail the limiting cases of the echo in the early-time and infinite-time limits, and provide scaling arguments to understand these in a general context. We also show that our perturbative results are in good agreement with the exact numerical ones.