Modeling long imperfect SNS junctions and Andreev bound states using two impurities and the T -matrix formalism
| Autor: | Vardan Kaladzhyan, C. Bena, Sarah Pinon |
|---|---|
| Přispěvatelé: | Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Royal Institute of Technology [Stockholm] (KTH ), European Project: 679722,QuantMatt - Grant agreement ID: 679722 |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
[PHYS]Physics [physics]
Physics T matrix Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Scattering FOS: Physical sciences 02 engineering and technology Electron 021001 nanoscience & nanotechnology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 01 natural sciences Andreev reflection Formalism (philosophy of mathematics) Impurity Condensed Matter::Superconductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Bound state Imperfect 010306 general physics 0210 nano-technology [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall] |
| Zdroj: | Physical Review B Physical Review B, American Physical Society, 2020, 101 (20), pp.205136. ⟨10.1103/PhysRevB.101.205136⟩ Physical Review B, 2020, 101 (20), pp.205136. ⟨10.1103/PhysRevB.101.205136⟩ |
| ISSN: | 2469-9950 2469-9969 |
| DOI: | 10.1103/PhysRevB.101.205136⟩ |
| Popis: | International audience; We provide a new analytical tool to calculate the energies of Andreev bound states (ABS) in long imperfect SNS junctions, at present these can only be described by numerical tools. We model an NS junction as a delta-function "Andreev" impurity, i.e., a localized potential which scatters an electron into a hole with opposite spin. We show using the scattering matrix formalism that, quite surprisingly, an "Andreev" impurity is equivalent to an NS junction characterized by both Andreev reflection and a finite amount of normal scattering. The ABS energies are then calculated using the T-matrix formalism applied to a system with two Andreev impurities. Our results lie between those for a perfect long SNS junction limit described by the Andreev approximation (ABS energies depend linearly on the phase and are independent of the chemical potential) and the particle-inthe-box limit (bound state energies are independent of the phase and have a linear dependence on the chemical potential). Moreover, we recover a closed-form expression for the ABS energies by expanding around the particle-in-the-box limit. |
| Databáze: | OpenAIRE |
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