A strong-driving toolkit for topological Floquet energy pumps with superconducting circuits

TL;DR

This paper demonstrates the experimental realization of topological Floquet energy pumps using superconducting transmon qubits, providing a practical toolkit for observing quantized energy currents driven by periodic modulation.

Contribution

It introduces an experimental toolkit for adiabatic driving of transmon qubits to realize topological energy pumping, bridging the gap between theory and direct observation.

Findings

Successful realization of adiabatic evolution over times comparable to T1

Development of a frequency and amplitude modulation toolkit

Paving the way for direct observation of topological energy pumping

Abstract

Topological Floquet energy pumps -- which use periodic driving to create a topologically protected quantized energy current -- have been proposed and studied theoretically, but have never been observed directly. Previous work proposed that such a pump could be realized with a strongly-driven superconducting qubit coupled to a cavity. Here, we experimentally demonstrate that the proposed hierarchy of energy scales and drive frequencies can be realized using a transmon qubit. We develop an experimental toolkit to realize the adiabatic driving field required for energy pumping using coordinated frequency modulation of the transmon and amplitude modulation of an applied resonant microwave drive. With this toolkit, we measure adiabatic evolution of the qubit under the applied field for times comparable to $T_1$, which far exceed the bare qubit dephasing time. This result paves the way for direct experimental observation of topological energy pumping.