Macroscopic Quantum Tunneling in a d -Wave High- T C Bi 2 Sr 2 CaCu 2 O 8 + δ Superconductor

摘要: While Josephson--junction-like structures intrinsic to the layered cuprate high temperature superconductors offer an attractive stage for exploiting possible applications new quantum technologies, low energy quasiparticle excitations characteristically present in these $d$-wave may easily destroy coherence required. Here we demonstrate first time feasibility of macroscopic tunneling Josephson junctions a superconductor ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$, and find it be characterized by classic-to-quantum crossover relatively weak dissipation.