Over the past decade, “non-Hermitian” systems have emerged across optics, electrical circuits, fluids, and condensed matter. Representing balanced loss and gain, such classical systems show enhanced sensing and robust topological transport [1]. Due to fluctuation-dissipation theorem and amplifier quantum noise, their realization in the quantum domain was challenging. I will show how non-Hermitian dynamics emerges in quantum systems ranging from the “small” (artificial atoms and trapped ions) to the “continuum” (quantum photonics). For the former, such dynamics result in enhanced temporal correlations [2], Floquet-stabilized states, and Jarzynski equality [3]. For the latter, such dynamics arise in a unitary system with squeezing [4], and can be used to simulate Lorentz transformations, the Wigner angle, and arbitrary (non-unitary) operations via singular-value decomposition.
*In collaboration with Alex Szameit (Rostock), Kater Murch (Wash U), Anthony Laing (Bristol), and David Allcock.
[1] A. Fritzsche et al., Nature Materials 23, 377 (2024).
[2] A. Quinn et al., arXiv:2304. 12413.
[3] S. Erdamar et al., arXiv:2309.12393.
[4] R. Wakefield et al., arXiv:2310.04523.