Crossed Andreev reflection in altermagnets

Abstract

Crossed Andreev reflection (CAR) is a scattering phenomenon occurring in a superconductor (SC) connected to two metallic leads, where an incident electron on one side of the SC emerges on the opposite side as a hole. Despite its significance, CAR detection is often impeded by the prevalent electron tunneling (ET), wherein the incident electron exits on the opposing side as an electron. One approach to augment CAR over ET involves employing two antiparallel ferromagnets across the SC. However, this method is constrained by the low polarization in ferromagnets and necessitates the application of a magnetic field. Altermagnets (AMs) present a promising avenue for detecting and enhancing CAR due to their distinct Fermi surfaces for the two spins. Here, we propose a configuration utilizing two AMs rotated by $90^{\circ }$ with respect to each other on either side of an SC to enhance CAR. We calculate local and nonlocal conductivities across the AM-SC-AM junction using the Landauer-Büttiker scattering approach. Our findings reveal that in the strong phase of AMs, CAR overwhelmingly dominates nonlocal transport. In the weak phase, CAR can exhibit significant enhancement for larger values of the altermagnetic parameter compared to the scenario where AMs are in the normal metallic phase. As a function of the length of the SC, the conductivities exhibit oscillations reminiscent of Fabry-Pérot interference.

12 pages, 9 captioned figures

References in corpus (37)

• Antiferromagnetic spintronics
• Universal Intrinsic Spin-Hall Effect
• Direct electronic measurement of the spin Hall effect
• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Momentum-Dependent Spin Splitting by Collinear Antiferromagnetic Ordering
• Andreev-Tunneling, Coulomb Blockade, and Resonant Transport of Non-Local Spin-Entangled Electrons
• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Giant and tunneling magnetoresistance effects from anisotropic and valley-dependent spin-momentum interactions in antiferromagnets
• Bottom-up design of spin-split and reshaped electronic band structures in spin-orbit-coupling free antiferromagnets: Procedure on the basis of augmented multipoles
• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Experimental observation of bias-dependent non-local Andreev reflection
• Crystal Thermal Transport in Altermagnetic RuO2
• Ubiquitous Superconducting Diode Effect in Superconductor Thin Films
• Distinct Fermi Surface Topology and Nodeless Superconducting Gap in (Tl0.58Rb0.42)Fe1.72Se2 Superconductor
• dc Josephson Effect in Altermagnets
• Near-unity Cooper pair splitting efficiency
• Andreev reflection at the altermagnet-superconductor interface
• Topological transition from nodal to nodeless Zeeman splitting in altermagnets
• Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe${}_{1.78}$Se${}_2$ probed by ARPES
• Phase-shifted Andreev levels in an altermagnet Josephson junction
• Sign of the crossed conductances at a FSF double interface
• Angle-resolved photoemission evidence of s-wave superconducting gap in KxFe2-ySe2 superconductor
• Orientation-dependent Josephson effect in spin-singlet superconductor/altermagnet/spin-triplet superconductor junctions
• Superconductor-altermagnet memory functionality without stray fields
• Perfect crossed Andreev reflection in Dirac hybrid junctions in the quantum Hall regime
• Transport across junctions of altermagnets with normal metals and ferromagnets
• Magnetic field induced Fabry-Pérot resonances in helical edge states
• Electrically controlled crossed Andreev reflection in two-dimensional antiferromagnets
• Enhancement of crossed Andreev reflection in a superconducting ladder connected to normal metal leads
• Superconducting spin filter
• Unitary limit in crossed Andreev transport
• Perfect crossed Andreev reflection in the proximitized graphene/superconductor/proximitized graphene junctions
• Enhancement of crossed Andreev reflection in a Kitaev ladder connected to normal metal leads
• Transconductance as a probe of nonlocality of Majorana fermions
• Tunable crossed Andreev reflection in a heterostructure consisting of ferromagnets, normal metal and superconductors
• Fabry-Pérot interference in Josephson junctions
• Transverse currents in spin transistors

Cited by in corpus (19)

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• Superconducting phenomena in systems with unconventional magnets
• Spin Splitting Nernst Effect in Altermagnet
• Spin-polarized Specular Andreev Reflections in Altermagnets
• All-electrically controlled spintronics in altermagnetic heterostructures
• Crossed Andreev reflection in collinear $p$-wave magnet/triplet superconductor junctions
• Transverse Spin current at the normal/p-wave magnet junctions
• Emergence of tunable exceptional points in altermagnet-ferromagnet junctions
• Floquet engineering spin triplet states in unconventional magnets
• Field-sensitive dislocation bound states in two-dimensional $d$-wave altermagnets
• Andreev bound states and supercurrent in an unconventional superconductor-altermagnetic Josephson junction
• Josephson diode effect in one-dimensional quantum wires connected to superconductors with mixed singlet-triplet pairing
• Light-induced Floquet spin-triplet Cooper pairs in unconventional magnets
• Néel vector controlled exceptional contours in $p$-wave magnet-ferromagnet junctions
• Viscoelastic tensor and hydrodynamics of altermagnets
• Orientation dependent anomalous Hall and spin Hall currents at junctions of altermagnets with $p$-wave magnets
• Multipole order in two-dimensional altermagnets
• Néel vector controlled charge and spin transport in altermagnetic junctions
• Manipulation of helical states revealed by crossed Andreev reflection