Andreev-reflection experiments on layered superconductors
| Autor: | Gernot Goll |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physics
Superconductivity Condensed matter physics Band gap Condensed Matter Physics Electronic Optical and Magnetic Materials Andreev reflection Reflection (mathematics) Condensed Matter::Superconductivity Bound state Charge carrier Electrical and Electronic Engineering Anomaly (physics) Electric current |
| Zdroj: | Physica B: Condensed Matter. 383:71-75 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/j.physb.2006.03.059 |
| Popis: | Excitations of a solid can be investigated by using ballistic electrons in point contacts as a probe. In particular, point-contact spectroscopy of normal metal–superconductor contacts is an important tool to study the symmetry and the nodal structure of the energy gap of the superconductor. The main mechanism for a current at low bias through a nanosized constriction is Andreev reflection of charge carriers at the interface between a normal metal and a superconductor. Andreev reflection leads to maxima in the differential conductance d I / d V vs. V . The position of the maxima depends not only on the size of the gap along given directions, but also on the order-parameter symmetry, the microscopic details of the contact and the barrier strength. In addition, if the order parameter exhibits a sign change an Andreev surface bound state leads to a conductance anomaly at zero bias. Here, recent investigations of some layered superconductors by point-contact spectroscopy are reviewed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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