Tunneling Anomaly in Superconductor above Paramagnetic Limit
| Autor: | B. L. Altshuler, I. L. Aleiner |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
Superconductivity
Physics Zeeman effect Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Superconductivity General Physics and Astronomy FOS: Physical sciences Electron Disordered Systems and Neural Networks (cond-mat.dis-nn) Condensed Matter - Disordered Systems and Neural Networks Superconductivity (cond-mat.supr-con) Physics::Fluid Dynamics Paramagnetism symbols.namesake Singularity Condensed Matter::Superconductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) symbols Density of states Anomaly (physics) Quantum tunnelling |
| Popis: | We study the tunneling density of states (DoS) in the superconducting systems driven by Zeeman splitting E_Z into the paramagnetic phase. We show that, even though the BCS gap disappears, superconducting fluctuations cause a strong DoS singularity in the vicinity of energies -E^* for electrons polarized along the magnetic field and E^* for the opposite polarization. The position of the singularity E^*=(1/2) (E_Z + \sqrt{E_Z^2- \Delta^2}) (where \Delta is BCS gap at E_Z=0) is universal. We found analytically the shape of the DoS for different dimensionality of the system. For ultrasmall grains the singularity has the form of the hard gap, while in higher dimensions it appears as a significant though finite dip. Our results are consistent with recent experiments in superconducting films. Comment: 4 pages, 2 .eps figures included |
| Databáze: | OpenAIRE |
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