Observation of Andreev Surface Bound States in the 3-K phase Region of Sr_2RuO_4
arXiv:cond-mat/0101410 · doi:10.1103/PhysRevLett.87.037003
Abstract
The tunneling spectrum of the superconducting phase with T_c ~ 3.0 K has been measured in the Ru-embedded region of Sr_2RuO_4 using cleaved junctions. A sharp zero-bias conductance peak (ZBCP) has been observed below 3 K. All characteristics of this ZBCP suggest that it originates from Andreev surface bound states, indicating that the pairing in the 3-K phase is also non-s-wave. Below the bulk T_c of Sr_2RuO_4 (~1.5 K), a bell-shaped ZBCP was found. This supports that there is a phase transition in the 3-K phase region near the bulk T_c.
4 pages, to appear in Phys. Rev. Lett. 87 (2001)