Proximity-induced gap in nanowires with a thin superconducting shell

@article{Kiendl2019ProximityinducedGI,
  title={Proximity-induced gap in nanowires with a thin superconducting shell},
  author={Thomas Kiendl and Felix von Oppen and Piet W. Brouwer},
  journal={Physical Review B},
  year={2019}
}
Coupling a normal metal wire to a superconductor induces an excitation gap in the normal metal. In the absence of disorder, the induced excitation gap is strongly suppressed by finite-size effects if the thickness of the superconductor is much smaller than the thickness of the normal metal and the superconducting coherence length. We show that the presence of disorder, either in the bulk or at the exposed surface of the superconductor, significantly enhances the magnitude of the induced gap… 

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References

SHOWING 1-10 OF 84 REFERENCES
Metallization of Rashba wire by superconducting layer in the strong-proximity regime
Semiconducting quantum wires defined within two-dimensional electron gases and strongly coupled to thin superconducting layers have been extensively explored in recent experiments as promising
Finite-size effects in a nanowire strongly coupled to a thin superconducting shell
We study the proximity effect in a one-dimensional nanowire strongly coupled to a finite superconductor with a characteristic size which is much shorter than its coherence length. Such geometries
Hard gap in a normal layer coupled to a superconductor
The ability to induce a sizable gap in the excitation spectrum of a normal layer placed in contact with a conventional superconductor has become increasingly important in recent years in the context
Elementary excitations in the vicinity of a normal metal-superconducting metal contact
The excitation spectrum of a slab of normal metal deposited on a superconducting substrate is discussed. It is shown that if the electron- electron attractive interaction is negligibly small in the
Proximity effect and Majorana bound states in clean semiconductor nanowires coupled to disordered superconductors
We model a semiconductor wire with strong spin-orbit coupling which is proximity-coupled to a superconductor with chemical potential disorder. When tunneling at the semiconductor-superconductor
To close or not to close: the fate of the superconducting gap across the topological quantum phase transition in Majorana-carrying semiconductor nanowires.
TLDR
It is found that the dependence of the end-of-wire local density of states on the magnetic field is nonuniversal and that the signatures associated with the closing of the superconducting gap at the Majorana TQPT are essentially invisible within a significant range of experimentally relevant parameters.
Correlations between Majorana fermions through a superconductor.
TLDR
It is demonstrated that besides the well-known direct-overlap-induced energy splitting, the two MF bound states may hybridize via elastic tunneling processes through virtual quasiparticle states in the SC, giving rise to an additional energy splitting between MF states from the same as well as from different wires.
Hard gap in epitaxial semiconductor-superconductor nanowires.
TLDR
The hard gap induced by the proximity effect in a semiconductor, using epitaxial InAs-Al semiconductor-superconductor nanowires, makes this new hybrid system attractive for a number of applications, as well as fundamental studies of mesoscopic superconductivity.
Effects of Gate-Induced Electric Fields on Semiconductor Majorana Nanowires
We study the effect of gate-induced electric fields on the properties of semiconductor-superconductor hybrid nanowires which represent a promising platform for realizing topological superconductivity
Helical liquids and Majorana bound states in quantum wires.
TLDR
It is argued that zero-energy Majorana bound states are formed in various situations when such wires are situated in proximity to a conventional s-wave superconductor when the external magnetic field, the superconducting gap, or the chemical potential vary along the wire.
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