Observing dynamical currents in a non-Hermitian momentum lattice
Abstract
We report on the experimental realization and detection of dynamical currents in a spin-textured lattice in momentum space. Collective tunneling is implemented via cavity-assisted Raman scattering of photons by a spinor Bose-Einstein condensate into an optical cavity. The photon field inducing the tunneling processes is subject to cavity dissipation, resulting in effective directional dynamics in a non-Hermitian setting. We observe that the individual tunneling events are superradiant in nature and locally resolve them in the lattice by performing real-time, frequency-resolved measurements of the leaking cavity field. The results can be extended to a regime exhibiting a cascade of currents and simultaneous coherences between multiple lattice sites, where numerical simulations provide further understanding of the dynamics. Our observations showcase dynamical tunneling in momentum-space lattices and provide prospects to realize dynamical gauge fields in driven-dissipative settings.
Cite
@article{arxiv.2108.11888,
title = {Observing dynamical currents in a non-Hermitian momentum lattice},
author = {Rodrigo Rosa-Medina and Francesco Ferri and Fabian Finger and Nishant Dogra and Katrin Kroeger and Rui Lin and R. Chitra and Tobias Donner and Tilman Esslinger},
journal= {arXiv preprint arXiv:2108.11888},
year = {2022}
}