Phase-Biased Andreev Diffraction Grating

TL;DR

This paper demonstrates phase-controlled Andreev diffraction in superconductor-semiconductor circuits, revealing multi-slit-like diffraction patterns through remote phase tuning, advancing understanding of quantum scattering phenomena.

Contribution

It introduces a novel phase-biased Andreev diffraction setup with remote phase control, extending diffraction concepts to superconducting hybrid systems.

Findings

Multiple Andreev scatterers produce diffraction patterns consistent with theory.

Remote phase tuning enables control over individual scatterer phases.

The system exhibits both local and nonlocal diffraction effects.

Abstract

In optical diffraction, the phase difference between sources in a grating or multi-slit mask is determined by the angle to the imaging screen, yielding the familiar multi-lobed diffraction image. Here, we realize a similar phenomenon in a superconductor-semiconductor hybrid circuit configured to allow Andreev scattering from multiple parallel scatterers. Phase differences between scatterers are set by tapping off of a remote superconducting meander. We investigate arrays with two, three, four, and ten Andreev scatterers, examining local and nonlocal diffraction patterns, finding good agreement with a theory of multiple Andreev scattering, not to be confused with multiple Andreev reflection. Adding current-carrying taps to the meander allows individual phase control.