High-T_c superconducting nanowires of Bi₂Sr₂CaCu₂O₈₊_dand quantum phase slips

Superconducting nanowires have attracted a great deal of interest in recent years because of their technological applications in diverse fields. It also provides answers to some of the fundamental questions of superconductivity in reduced dimensions. As one approaches lower and lower form factor of nanowires, effects of fluctuations become important, one particular example being quantum phase slips (QPS). Although at the outset QPS may seem undesirable they offer some interesting avenues for applications. It has been proposed that superconducting nanowires can be used in realizing qubits for quantum computing exploiting the QPS. Nanowires with high superconducting transition temperature (T_c) would greatly help in that direction. Apart from that superconducting nanowire can be used as a sensitive photon detector.  Here we report a novel scalable route to make nanowires of a high-T_c superconductor Bi₂Sr₂CaCu₂O_8+d having T_c of 85 K. Measurements on these as-fabricated nanowires suggest existence of QPS. We also show these nanowires can be used as a sensitive detector for radiation in the visible range.