Abstract
The observation that -symmetric Hamiltonians can have real-valued energy levels even if they are non-Hermitian has triggered intense activities, with experiments, in particular, focusing on optical systems, where Hermiticity can be broken by absorption and amplification. For classical waves, absorption and amplification are related by time-reversal symmetry. This work shows that microreversibility-breaking quantum noise turns -symmetric systems into self-sustained sources of radiation, which distinguishes them from ordinary, Hermitian quantum systems.
- Received 6 January 2010
DOI:https://doi.org/10.1103/PhysRevLett.104.233601
©2010 American Physical Society