Emergence of Boltzmann subspaces in open quantum systems far from equilibrium

By Michael Iv

Done under supervision of Prof. Uri Peskin

Single-molecule junctions are examples of complex many-body quantum systems far from equilibrium. Within these systems, we observe a non-trivial clustering of steady-state populations into unique subspaces that exhibit Boltzmann-like statistics, which we coin Boltzmann subspaces. These subspaces maintain their characteristics even in the absence of equilibrium. Moreover, they can play a crucial role in minimizing the information required to characterize the steady state of open quantum systems by enabling the modeling of high-dimensional systems that would otherwise exceed current computational capabilities. We demonstrate the emergence of Boltzmann subspaces through both analytical and numerical analyses conducted on fermionic transport systems of escalating complexity. The investigation of the bosonic case was solely handled through numerical methods. For future research, I propose extending our approach to encompass bosonic systems using graph theory.