Andreev reflection in YBa2Cu3O7−δ∕La0.67Ca0.33MnO3: Existence of midgap states in the {110} surface of YBa2Cu3O7−δ
P. S. Luo, H. Wu, F. C. Zhang, C. Cai, X. Y. Qi, X. L. Dong, W. Liu, X. F. Duan, B. Xu, L. X. Cao, X. G. Qiu, B. R. Zhao
DOI 10.1103/PhysRevB.71.094502 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We use interfacial transport and transmission electron microscopy to study the YBa2Cu3O7−δ(YBCO)∕La0.67Ca0.33MnO3(LCMO) junction that form a dx2−y2-wave superconductor and a ferromagnet (FM) heterostructure. Zero bias conductance peaks (ZBCPs) caused by Andreev reflection at zero bias were observed in the interfacial differential conductance spectra for the sample with an orderly mixed c- and a-axis [with (001) and (100)∕(110)] orientation of YBCO in the interface. When the YBCO film is oriented with the c-axis normal to the interface, a zero bias conductance dip (ZBCD) is observed. These results evidence the existence of surface Andreev bound states (midgap states) in the {110} surface of YBCO, which can lead ZBCP to appear in all directions except the {100} surface of YBCO where ZBCD occurs. Furthermore, the absence of any obvious influence of spin-polarization of LCMO on ZBCP in zero magnetic field implies that the LCMO is not half-metallic in the interface of YBCO∕LCMO, while strong magnetic field dependence of ZBCP shows that the applied magnetic field enhances the spin polarization of LCMO and suppresses ZBCPs in YBCO.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| YBa2Cu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 82 | Pressure not reported | unknown |
| YBa2Cu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 91 | Pressure not reported | unknown |
Similar papers
Observation of quasiparticle Andreev bound states using YBa2Cu3O7−y/Ag ramp-edge junctions with different interface geometries
similarity 0.95Wan Wang et al.
Source status unknown — claims are unverified
Evidence for crossed Andreev reflections in bilayers of (100) YBa2Cu3O7−δ and the itinerant ferromagnet SrRuO3
similarity 0.95Itay Asulin et al.
Source status unknown — claims are unverified
Andreev Reflections on Y1−xCaxBa2Cu3O7−δ: Evidence for an Unusual Proximity Effect
similarity 0.95A. Kohen et al.
Source status unknown — claims are unverified
Spin-polarized transport across a La0.7Sr0.3MnO3/YBa2Cu3O7−x interface: Role of Andreev bound states
similarity 0.95Z. Y. Chen et al.
Source status unknown — claims are unverified
Angle-resolved Andreev bound states in anisotropic d-wave high-Tc YBa2Cu3O7−y superconductors
similarity 0.94I. Iguchi et al.
Source status unknown — claims are unverified
Measurements of Δ and vF from Andreev reflections and McMillan-Rowell oscillations in edge junctions of YBa2Cu3O6.6/YBa2Cu2.55Fe0.45Oy/YBa2Cu3O6.6
similarity 0.93O. Nesher & G. Koren
Source status unknown — claims are unverified