# KTaO3‑Based Supercurrent Diode

## TL;DR

Researchers demonstrated a supercurrent diode effect using a LAO/KTO interface, enabling nonreciprocal superconducting currents with potential applications in quantum circuits.

## Contribution

A reconfigurable superconducting weak link platform at the LAO/KTO interface is introduced to realize the supercurrent diode effect.

## Key findings

- The supercurrent diode effect is achieved using nanoscale weak link geometry at the LAO/KTO interface.
- The rectification efficiency reaches up to 13% under optimal magnetic field conditions.
- Asymmetric vortex motion due to inversion-symmetry-breaking geometry explains the observed effect.

## Abstract

The supercurrent diode effect (SDE), characterized by
nonreciprocal
critical currents, represents a promising building block for future
dissipationless electronics and quantum circuits. Realizing SDE requires
breaking both time-reversal and inversion symmetry in the device.
Here we use conductive atomic force microscope (c-AFM) lithography
to pattern reconfigurable superconducting weak links (WLs) at the
LaAlO3/KTaO3 (LAO/KTO) interface. By deliberately
engineering the WL geometry at the nanoscale, we realize SDE in these
devices in the presence of modest out-of-plane magnetic fields. The
SDE polarity can be reversed by simply changing the WL position, and
the rectification efficiency reaches up to 13% under optimal magnetic
field conditions. Time-dependent Ginzburg–Landau simulations
reveal that the observed SDE originates from asymmetric vortex motion
in the inversion-symmetry-breaking device geometry. This demonstration
of SDE in the LAO/KTO system establishes a versatile platform for
investigating and engineering vortex dynamics, forming the basis for
engineered quantum circuit elements.