001030127 001__ 1030127
001030127 005__ 20250203103326.0
001030127 0247_ $$2doi$$a10.48550/ARXIV.2408.07035
001030127 037__ $$aFZJ-2024-05233
001030127 1001_ $$0P:(DE-Juel1)190987$$aKruti, Daniel$$b0$$ufzj
001030127 245__ $$aImpact of evanescent scattering modes and finite dispersion in superconducting junctions
001030127 260__ $$barXiv$$c2024
001030127 3367_ $$0PUB:(DE-HGF)25$$2PUB:(DE-HGF)$$aPreprint$$bpreprint$$mpreprint$$s1724063081_30118
001030127 3367_ $$2ORCID$$aWORKING_PAPER
001030127 3367_ $$028$$2EndNote$$aElectronic Article
001030127 3367_ $$2DRIVER$$apreprint
001030127 3367_ $$2BibTeX$$aARTICLE
001030127 3367_ $$2DataCite$$aOutput Types/Working Paper
001030127 520__ $$aSuperconducting junctions are essential building blocks for quantum hardware, and their fundamental behavior remains a highly active research field. The behaviour of generic junctions is conveniently described by Beenakker's determinant formula, linking the subgap energy spectrum to the scattering matrix characterizing the junction. In particular, the gap closing between bound and continuum states in short junctions follows from unitarity of the scattering matrix, and thus, from probability conservation. In this work, we critically reassess two assumptions: that scattering in short junctions is approximately energy-independent and dominated by planar channels. We argue that strongly energy-dependent scattering follows from finite dispersion of the conductor electrons even when they spend little time within the scattering region, and show that evanescent modes play a central role when cross-channel scattering is important. By generalizing Beenakker's equation and performing a mapping to an effective Hamiltonian, we show that the gap closing is linked to a chiral symmetry. While finite energy-dependence in the scattering breaks the chiral symmetry, we show two distinct mechanisms preserving the gap closing, each connected to new types of constraints on energy-dependent scattering matrices beyond unitarity. If the dispersive mode is planar, the gap closing is still preserved through a time-dependent probability conservation analysis of the scattering process. If the dispersive channel is evanescent, we derive a constraint which, notably, cannot follow from probability conservation. We thus demonstrate that Andreev physics reveal a much wider variety of properties of normal metal scattering than commonly expected. We expect that our findings will have an impact on the dissipative behavior of driven junctions, and offer a new perspective on fundamental properties of scattering matrices.
001030127 536__ $$0G:(DE-HGF)POF4-5221$$a5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522)$$cPOF4-522$$fPOF IV$$x0
001030127 588__ $$aDataset connected to DataCite
001030127 650_7 $$2Other$$aMesoscale and Nanoscale Physics (cond-mat.mes-hall)
001030127 650_7 $$2Other$$aOther Condensed Matter (cond-mat.other)
001030127 650_7 $$2Other$$aSuperconductivity (cond-mat.supr-con)
001030127 650_7 $$2Other$$aFOS: Physical sciences
001030127 7001_ $$aRiwar, Roman-Pascal$$b1
001030127 773__ $$a10.48550/ARXIV.2408.07035
001030127 909CO $$ooai:juser.fz-juelich.de:1030127$$pVDB
001030127 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)190987$$aForschungszentrum Jülich$$b0$$kFZJ
001030127 9131_ $$0G:(DE-HGF)POF4-522$$1G:(DE-HGF)POF4-520$$2G:(DE-HGF)POF4-500$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF4-5221$$aDE-HGF$$bKey Technologies$$lNatural, Artificial and Cognitive Information Processing$$vQuantum Computing$$x0
001030127 9141_ $$y2024
001030127 9201_ $$0I:(DE-Juel1)PGI-2-20110106$$kPGI-2$$lTheoretische Nanoelektronik$$x0
001030127 980__ $$apreprint
001030127 980__ $$aVDB
001030127 980__ $$aI:(DE-Juel1)PGI-2-20110106
001030127 980__ $$aUNRESTRICTED