Observing Dynamical Currents in a Non-Hermitian Momentum Lattice

Area of Science:

• Quantum physics
• Atomic, molecular, and optical (AMO) physics
• Condensed matter physics

Background:

• Dynamical tunneling is a quantum mechanical phenomenon where particles can move between localized states.
• Spin-textured lattices offer unique properties for controlling quantum states.
• Driven-dissipative systems are open quantum systems interacting with their environment.

Purpose of the Study:

• To experimentally realize and detect dynamical currents in a spin-textured lattice in momentum space.
• To investigate the role of cavity dissipation in creating directional dynamics.
• To explore the potential for realizing dynamical gauge fields.

Main Methods:

• Cavity-assisted Raman scattering of photons by a spinor Bose-Einstein condensate into an optical cavity.
• Real-time, frequency-resolved measurements of the leaking cavity field.
• Numerical simulations to understand complex dynamics.

Main Results:

• Experimental observation of collective tunneling and superradiant tunneling events.
• Local resolution of individual tunneling events in the lattice.
• Demonstration of directional dynamics in a non-Hermitian setting due to cavity dissipation.

Conclusions:

• The study successfully showcases dynamical tunneling in momentum-space lattices.
• The findings provide a pathway towards realizing dynamical gauge fields in driven-dissipative systems.
• The experimental approach offers new possibilities for controlling quantum dynamics.