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Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Andreev spectra and subgap bound states in multiband superconductors
A A Golubov1, A Brinkman, Yukio Tanaka
1MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
Physical Review Letters
|October 2, 2009
Summary
We developed a theory for Andreev conductance in junctions with multiband superconductors, revealing unique signatures for extended s(+/-)-wave symmetry possibly found in ferropnictides.
Area of Science:
- Condensed Matter Physics
- Superconductivity Theory
Background:
- Superconductors with extended s(+/-)-wave order parameter symmetry, potentially found in ferropnictides, exhibit unique electronic properties.
- Understanding Andreev conductance is crucial for characterizing superconducting states.
Purpose of the Study:
- To formulate a theory of Andreev conductance for normal metal/multiband superconductor junctions.
- To investigate the specific case of nodeless extended s(+/-)-wave superconductors.
- To identify unique signatures distinguishing this state from s-wave or d-wave superconductors.
Main Methods:
- Theoretical formulation of Andreev conductance.
- Application to multiband superconductors with extended s(+/-)-wave symmetry.
- Analysis of interband interference effects.
Main Results:
- Qualitative differences in Andreev conductance compared to s-wave and d-wave superconductors.
- Suppression of Andreev reflection at highly transparent interfaces due to interband interference.
- Appearance of surface bound states at zero and nonzero energies.
Conclusions:
- The developed theory provides a framework for identifying extended s(+/-)-wave superconductors.
- Observed phenomena like current deficit and surface bound states serve as potential experimental fingerprints.
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