Doubly Modulated Optical Lattice Clock: Interference and Topology

The quantum system under periodical modulation is the simplest path to understand the quantum nonequilibrium system because it can be well described by the effective static Floquet Hamiltonian. Under the stroboscopic measurement, the initial phase is usually irrelevant. However, if two uncorrelated parameters are modulated, their relative phase cannot be gauged out so that the physics can be dramatically changed. Here, we simultaneously modulate the frequency of the lattice laser and the Rabi frequency in an optical lattice clock (OLC) system. Thanks to the ultrahigh precision and ultrastability of the OLC, the relative phase could be fine-tuned. As a smoking gun, we observed the interference between two Floquet channels. Finally, by experimentally detecting the eigenenergies, we demonstrate the relation between the effective Floquet Hamiltonian and the one-dimensional topological insulator with a high winding number. Our experiment not only provides a direction for detecting the phase effect but also paves a way in simulating the quantum topological phase in the OLC platform.

Automated summary

By modulating the frequency and Rabi frequency in an optical lattice clock system, the interference between two Floquet channels was observed, demonstrating the relation between the effective Floquet Hamiltonian and a one-dimensional topological insulator with a high winding number. This experiment not only provides a direction for detecting phase effects, but also paves the way for simulating quantum topological phases in the OLC platform.