Universal scaling at a prethermal dark state

Recent experimental and theoretical progress as well as the prospect of commercially viable quantum technologies have inspired great interest in the study of open quantum systems and their dynamics. Many open quantum systems are well described by an effective non-Hermitian Hamiltonian generating a time evolution that allows eigenstates to decay and dissipate to the environment. In this framework, quantum coherent scaling is traditionally tied to the appearance of dark states, where the effect of dissipation becomes negligible. Here, we discuss the universal dynamical scaling after a sudden quench of the non-Hermitian O(N) model Hamiltonian. While universality is generally spoiled by non-Hermiticity, we find that for a given set of internal parameters short-time scaling behavior is restored with an initial slip exponent profoundly different from that of closed quantum systems. This result is tied to the compensation of dissipation by interaction effects at short times leading to a prethermal dark state, where coherent many-body dynamics can be still observed.

Automated summary

Recent progress in the study of open quantum systems, coupled with the potential for commercially viable quantum technologies, has sparked significant interest. Many open quantum systems can be described by a non-Hermitian Hamiltonian, allowing for decay and dissipation to occur. In this paper, we discuss the universal dynamical scaling in the non-Hermitian O(N) model Hamiltonian after a sudden quench. We find that, despite the disruption of universality due to non-Hermiticity, the short-time scaling behavior can be restored, showcasing the compensation of dissipation by interaction effects and the emergence of a prethermal dark state where coherent many-body dynamics can still be observed.