Krasnov V M, Kovalev A E, Yurgens A, Winkler D
Department of Microelectronics and Nanoscience, Chalmers University of Technology, Göteborg, Sweden.
Phys Rev Lett. 2001 Mar 19;86(12):2657-60. doi: 10.1103/PhysRevLett.86.2657.
Intrinsic tunneling spectroscopy in high magnetic field (H) is used for a direct test of superconducting features in the quasiparticle density of states of pure Bi2212 and intercalated HgBr2-Bi2212 high- T(c) superconductors. We were able to distinguish with great clarity two coexisting gaps: (i) the superconducting gap, which closes as H-->H(c2)(T), and (ii) the c-axis pseudogap, which does not change either with H or with T. Strikingly different H dependencies, together with previously observed different temperature dependencies of the two gaps, speak against a superconducting origin of the pseudogap.
高磁场（H）下的本征隧穿光谱用于直接测试纯Bi2212和插层HgBr2 - Bi2212高温超导体准粒子态密度中的超导特性。我们能够非常清晰地区分两个共存的能隙：（i）超导能隙，当H→Hc2（T）时闭合；（ii）c轴赝能隙，其不随H或T变化。两种能隙截然不同的磁场依赖性，以及之前观察到的它们不同的温度依赖性，都表明赝能隙并非源于超导。
