Suppressed Superconductivity of the Surface Conduction Layer in Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ Single Crystals Probed by {it c}-Axis Tunneling Measurements

Дата и время публикации : 1998-08-11T01:49:13Z

Авторы публикации и институты :
Nam Kim
Yong Joo Doh
Hyun-Sik Chang
Hu-Jong Lee

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 13 pages, 6 figures
Первичная категория: cond-mat.supr-con

Все категории : cond-mat.supr-con

Краткий обзор статьи: We fabricated small-size stacks on the surface of Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO-2212) single crystals with the bulk transition temperature $T_c$$simeq$90 K, each containing a few intrinsic Josephson junctions. Below a critical temperature $T_c’$ ($ll$ $T_c$), we have observed a weakened Josephson coupling between the CuO$_2$ superconducting double layer at the crystal surface and the adjacent one located deeper inside a stack. The quasiparticle branch in the $IV$ data of the weakened Josephson junction (WJJ) fits well to the tunneling characteristics of a d-wave superconductor($’$)/insulator/d-wave superconductor (D$’$ID) junction. Also, the tunneling resistance in the range $T_c’$$<$$T$$<$$T_c$ agrees well with the tunneling in a normal metal/insulator/d-wave superconductor (NID) junction. In spite of the suppressed superconductivity at the surface layer the symmetry of the order parameter appears to remain unaffected.

Category: Physics