Speaker: Andrew Lingenfelter
Affiliation: IQOQI, Innsbruck
Date: Tuesday, 10 March 2026 at 12:00
Location: Online seminar
Driven-dissipative many-body systems are typically driven toward nonequilibrium steady states due to the competition between coherent and dissipative dynamics. Exact steady states solutions of these models can offer insight into this competition. Remarkably, there is a class of driven-dissipative models which possess a “hidden” time-reversal symmetry (TRS) and, thus, have exactly solvable steady states, even in the presence of interactions. Many examples of bosonic and spin systems with hidden time-reversal symmetry have been solved; however, it had not been known whether hidden TRS can exist in fermionic systems.
In this talk I will discuss this notion of time-reversal symmetry and its connection exact solutions by way of an example: a boundary driven dissipative spin chain. Then I will discuss how the exact solution technique can be adapted to fermionic systems, and I will present the exact steady state solutions of interacting fermionic model: a 1D lattice of fermions with nearest neighbor p-wave pairing and a global charging energy. The model exhibits a first order phase transition between high- and low-density phases, and its dynamics are shown to be constrained by the hidden TRS, which shows that the symmetry can exist in fermionic systems.