Superconducting proximity effects in Pb nano-islands

Time 2015-11-12 15:30~16:00 Place Room 601+602
Code No. ME-I09 Session Chair
Name Prof. Jungdae Kim
Affiliation University of Ulsan
Title Superconducting proximity effects in Pb nano-islands
Contents
An intriguing lateral proximity effect was discovered from Pb nano-islands. The proximity effect is a central feature of superconducting junctions that plays a key role in many devices and can be exploited in the design of new systems with quantum functionality. Recently, exotic proximity effects have been observed in various systems, including superconductor–metallic nanowires and graphene–superconductor structures. However, it is still not clear how superconducting order propagates spatially in a heterogeneous superconductor system. I will present intriguing junction geometry effects in a heterogeneous system consisting of electronically two-dimensional superconducting islands on a metallic substrate. Depending on the local geometry, the superconducting gap induced at the metallic surface sometimes decays within ~ 20nm of the superconductor, and sometimes survives at distances that are several coherence lengths from a superconductor. I will show in particular that the curvature of the junction plays an essential role in the proximity effect. [Reference] 1. Jungdae Kim, Victor Chua, Gregory A. Fiete, Hyoungdo Nam, A. H. MacDonald, and Chih-Kang Shih, Nature Phys. 8, 465 (2012) 2. Jungdae Kim, Gregory A. Fiete, Hyoungdo Nam, A. H. MacDonald, and Chih-Kang Shih, Phys. Rev. B 84, 014517 (2011) 3. Shengyong Qin, Jungdae Kim, Q. Niu, and Chih-Kang Shih, Science 324, 1314 (2009)