La2−xSrxCuO4 Superconductor Nanowire Devices
Figure 1: Typical AFM and mutual inductance data of LSCO films. (A) An AFM image of an ALL-MBE-grown LSCO film, showing the rms surface roughness less than 3 Å, over a 9 μm2 scan area. (B) The imaginary part of the mutual inductance of an optimally doped, 20 unit cell thick LSCO film, showing Tc = 41 K. [From:N.E. Litombe, A.T. Bollinger, J.E. Hoffman, I. Božović, "La2−xSrxCuO4 Superconductor Nanowire Devices," Physica C, v.506 (15 Nov 2014)]
La2−xSrxCuO4 nanowire devices have been fabricated and characterized using electrical transport measurements. Nanowires with widths down to 80 nm are patterned using high-resolution electron beam lithography. However, the narrowest nanowires show incomplete superconducting transitions with some residual resistance at T = 4 K.
In a new paper in Physica C, Prof. Jenny Hoffman and colleagues from Harvard and Brookhaven National Laboratory report on the refinement of the fabrication process to achieve narrower nanowire devices with complete superconducting transitions, opening the path to the study of novel physics arising from dimension-limited superconductivity on the nanoscale.