Phase diagram of the electron-doped La2-xCexCuO4 cuprate superconductor from Andreev bound states at grain boundary junctions |
| |
Authors: | Wagenknecht M Koelle D Kleiner R Graser S Schopohl N Chesca B Tsukada A Goennenwein S T B Gross R |
| |
Affiliation: | Physikalisches Institut-Experimentalphysik II and Center for Collective Quantum Phenomena, Universit?t Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany. wagenknecht@uni-tuebingen.de |
| |
Abstract: | We use quasiparticle tunneling across La2-xCexCuO4 grain boundary junctions to probe the superconducting state and its disappearance with increasing temperature and magnetic field. A zero bias conductance peak due to zero energy surface Andreev bound states is a clear signature of the phase coherence of the superconducting state. Hence, such a peak must disappear at or below the upper critical field Bc2(T). For La2-xCexCuO4 this approach sets a lower bound for Bc2(0) approximately 25 T which is substantially higher than reported previously. The method of probing the superconducting state via Andreev bound states should also be applicable to other cuprate superconductors. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |