Radio-Frequency Quantum Rectification in Kagome Superconductor CsV3Sb5

TL;DR

This paper reports the first experimental demonstration of quantum rectification in the kagome superconductor CsV3Sb5, showing frequency-dependent DC voltage generation and quantized steps, advancing quantum power and communication technologies.

Contribution

It introduces the realization of radio-frequency quantum rectification in CsV3Sb5, combining superconducting diode effects with Josephson effects in a novel material platform.

Findings

DC voltage scales linearly with frequency as V = hf/2e

Rectified voltage shows quantized Shapiro steps

CsV3Sb5 hosts emergent Josephson effects and zero-field diode behavior

Abstract

Rectification of electromagnetic fields into direct current (DC) is pivotal for energy harvesting, wireless charging, and next-generation communication technologies. The superconducting diode effect, which exploits the nonreciprocal transport of dissipationless superconducting currents, offers ultra-low power consumption and high rectification ratios. Combining the superconducting diode effect with the AC Josephson effect holds promise for converting radio-frequency (rf) irradiation into a quantized DC output. However, experimental realization has been hindered by challenges in achieving the necessary symmetry breaking and fabricating high-performance Josephson junctions. Here we demonstrate the quantum rectification in kagome superconductor CsV3Sb5, which hosts emergent Josephson effects and a zero-field Josephson diode. Under rf irradiation, a DC voltage emerges without applied bias, scaling linearly with frequency as V = hf/2e, where h is Planck's constant, f is the microwave frequency, and e is the electron charge. Furthermore, the rectified voltage exhibits quantized steps with increasing rf power, consistent with Shapiro step quantization. Our work establishes CsV3Sb5 as a versatile platform for wireless quantum power supplies and charging, and underscores the intertwined order parameters as a promising pathway for precise quantum matter control.