Photoresponse of a La1.85Sr0.15CuO4 nanostrip

We report on the fabrication and photoresponse of a 5 nm thick La1.85Sr0.15CuO4 nanostrip with a width of 100 nm. The I–V characteristics of the nanostrip show a hysteresis and a sharp voltage jump at critical current (I c). The critical current density J c (3 K) of the nanostrip is 2.3 × 107 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 using the La1.85Sr0.15CuO4 nanostrip as a single-photon detector working at high temperature by further reducing the cross-section of the strip.