Pramana | |
Anomalous density of states in hybrid normalmetal–superconductor bilayers | |
A K Gupta12  L Crétinon1  B Pannetier1  H Courtois1  | |
[1] Centre de Recherches sur les Très Basses Températures - C.N.R.S. associé à l'Université Joseph Fourier, 25 Avenue des Martyrs, 38042 Grenoble, France$$;Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208 016, India$$ | |
关键词: Proximity effect; density of states; Andreev reflection.; | |
DOI : | |
学科分类:物理(综合) | |
来源: Indian Academy of Sciences | |
【 摘 要 】
In contact with a superconductor, the Andreev reflection of the electronslocally modifies the N metal electronic properties, including the local density of states(LDOS). We investigated the LDOS in superconductor–normal metal (Nb–Au) bilayersusing a very low temperature (60 mK) STM on the normal metal side. High resolutiontunneling spectra measured on the Au surface show a clear proximity effect with an energygap of reduced amplitude compared to the bulk Nb gap. The dependence of this mini-gap width with the normal metal thickness is discussed in terms of the Thouless energy. Within the mini-gap, the density of states does not reach zero and shows clear sub-gapfeatures. We compare the experimental spectra with the well-established quasi-classicaltheory.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
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RO201912040497025ZK.pdf | 391KB | download |