Non-adiabatic linear response in open quantum systems

TL;DR

This paper extends non-adiabatic linear response theory to open quantum many-body systems, revealing how different ramping protocols probe correlations and steady-state properties.

Contribution

It generalizes the theory to open systems, showing the response depends on the type of parameter ramping and introduces a new way to probe many-body correlations.

Findings

First-order deviation is memoryless and depends only on final parameters.

Ramping Hamiltonian involves the derivative of the retarded Green's function.

Ramping dissipation involves a high-order correlation function.

Abstract

Adiabatic theorem and non-adiabatic corrections have been widely applied in modern quantum technology. Recently, non-adiabatic linear response theory has been developed to probe the many-body correlations in closed systems. In this work, we generalize the non-adiabatic linear response theory to open quantum many-body systems. We show that, similar to the closed case, the first-order deviation from the instantaneous steady state is memoryless -- it depends only on the final parameters and not on the initial state or ramping path. When ramping the Hamiltonian, the linear response of observables is governed by the derivative of the retarded Green's function, as in closed systems. In contrast, ramping the dissipation gives rise to a different response, characterized by a high-order correlation function defined in the steady state. Our results offer a compact and physically transparent formulation of non-adiabatic response in open systems, and demonstrate that ramping dynamics can serve as a versatile tool for probing many-body correlations beyond equilibrium.