Interfering Josephson diode effect in Ta2Pd3Te5 asymmetric edge interferometer

TL;DR

This paper demonstrates a superconducting edge interferometer on topological insulator Ta2Pd3Te5 that exhibits a highly efficient Josephson diode effect with low power consumption, confirmed by second harmonic measurements and asymmetric transport.

Contribution

It introduces a novel asymmetric edge interferometer on Ta2Pd3Te5 that significantly enhances Josephson diode effect performance and provides experimental confirmation of the underlying second harmonic current-phase relation.

Findings

Achieved up to 73% efficiency in Josephson diode effect at low magnetic fields.

Confirmed second harmonic in current-phase relation via half-integer Shapiro steps.

Demonstrated asymmetry in transport correlating with JDE polarity.

Abstract

Edge states in topological systems have attracted great interest due to their robustness and linear dispersions. Here a superconducting-proximitized edge interferometer is engineered on a topological insulator Ta2Pd3Te5 with asymmetric edges to realize the interfering Josephson diode effect (JDE), which hosts many advantages, such as the high efficiency as much as 73% at tiny applied magnetic fields with an ultra-low switching power around picowatt. As an important element to induce such JDE, the second-order harmonic in the current-phase relation is also experimentally confirmed by half-integer Shapiro steps. The interfering JDE is also accompanied by the antisymmetric second harmonic transport, which indicates the corresponding asymmetry in the interferometer, as well as the polarity of JDE. This edge interferometer offers an effective method to enhance the performance of JDE, and boosts great potential applications for future superconducting quantum devices.