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

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.