Floquet-Multiple Andreev Reflections

TL;DR

This paper explores Floquet theory applied to voltage-biased multiterminal Josephson junctions, revealing Floquet-MAR conductance and noise resonances that could enable new quantum device functionalities.

Contribution

It introduces the concept of Floquet-MAR processes in multiterminal Josephson junctions, providing a microscopic understanding of their finite-bias conductance and noise features.

Findings

Floquet-MAR processes produce characteristic conductance resonances.

Higher-order multipair processes lead to distinct Floquet signatures.

The study offers a pathway to experimentally probe Floquet-MAR physics.

Abstract

Floquet theory describes quantum systems governed by time-periodic Hamiltonians, much as Bloch theory describes spatially periodic solids. In voltage-biased multiterminal Josephson junctions, the Josephson relation causes superconducting phase differences to evolve periodically in time, thereby providing an intrinsic Floquet drive. In this Letter, we consider three-terminal Josephson junctions formed on a ballistic two-dimensional normal conductor with a continuum of electronic states. We show that the quartet and higher-order multipair processes yield characteristic Floquet-multiple Andreev reflection (Floquet-MAR) finite-bias conductance and noise resonances that are parameterized by the bias voltage and electrochemical potential. This microscopic picture opens a route toward implementing and probing Floquet-MAR physics in ballistic multiterminal Josephson junctions.