Photoresponse of La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrip

TL;DR

This study demonstrates the fabrication and photoresponse of ultra-thin La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrips, showing potential for high-temperature single-photon detection applications.

Contribution

The paper reports the creation of 5 nm thick La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrips with notable photoresponse, indicating their potential as high-temperature SSPDs.

Findings

Nanostrips exhibit photoresponse signals at 1560 nm wavelength.

Photoresponse diminishes with lower optical intensity and higher temperature.

Nanostrips can operate up to 30 K, higher than typical superconducting detectors.

Abstract

We report the fabrication and photoresponse of 5 nm thick La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrip with a width of 100nm. The I-V characteristics of the nanostrip show a hysteresis and a sharp voltage jump at $I_{c}$. The $J_{c}$(3K) of the nanostrip is 2.3 x 10$^{7}$ A/cm$^{2}$. The nanostrip exhibits photoresponse signals when illuminated by a pulse laser at 1560 nm wavelength with a bias current just below $I_{c}$. The height of the signal reduces as the optical intensity decreases and disappears below -10 dBm. The signal also decreases as the temperature increases, but it exists up to 30 K. These results suggest the possibility of La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ nanostrip as single-photon detector (SSPD, SNSPD) working at high temperature by further reducing the cross-section of the strip.