Abstract:
Floquet modulation has been widely used in optical lattices for coherent
control of quantum gases, in particular for synthesizing artificial gauge
fields and simulating topological matters. However, such modulation induces
heating which can overwhelm the signal of quantum dynamics in ultracold atoms.
Here we report that the thermal motion, instead of being a noise source,
provides a new control knob in Floquet-modulated superradiance lattices, which
are momentum-space tight-binding lattices of collectively excited states of
atoms. The Doppler shifts combined with Floquet modulation provide effective
forces along arbitrary directions in a lattice in frequency and momentum
dimensions. Dynamic localization, dynamic delocalization and chiral edge
currents can be simultaneously observed from a single transport spectrum of
superradiance lattices in thermal atoms. Our work paves a way for simulating
Floquet topological matters in room-temperature atoms and facilitates their
applications in photonic devices.