Physics

T-symmetry

Reciprocity (cultural anthropology)

Symmetry (geometry)

Mathematics

Statistical physics

Phase transition

Criticality

Dissipation

Psychology

Symmetry breaking

Nuclear physics

Geometry

Theoretical physics

Ising model

Superconductivity

Quantum mechanics

Observable

Social psychology

Dissipative system

Statistical mechanics

SciPost Physics

Fluctuation-dissipation relations (FDRs) and time-reversal symmetry (TRS), two pillars of statistical mechanics, are both broken in generic driven-dissipative systems. These systems rather lead to non-equilibrium steady states far from thermal equilibrium. Driven-dissipative Ising-type models, however, are widely believed to exhibit effective thermal critical behavior near their phase transitions. Contrary to this picture, we show that both the FDR and TRS are broken even macroscopically at, or near, criticality. This is shown by inspecting different observables, both even and odd operators under time-reversal transformation, that overlap with the order parameter. Remarkably, however, a modified form of the FDR as well as TRS still holds, but with drastic consequences for the correlation and response functions as well as the Onsager reciprocity relations. Finally, we find that, at criticality, TRS remains broken even in the weakly-dissipative limit.

Time-reversal symmetry breaking and emergence in driven-dissipative Ising models