Andreev Reflection In Spin Polarised Superconductor

Selective equal spin Andreev reflection at vortex core center in.
Spin-resolved Andreev levels and parity crossings in hybrid... - Nature.
Spin polarized transport as measured by superconducting.
PDF Andreev experiments on superconductor/ferromagnet point contacts - CORE.
Andreev Reflection - an overview | ScienceDirect Topics.
Andreev Reflection in Ferromagnet/Superconductor/Ferromagnet.
PDF Magnetoanisotropic Andreev Reflection in Ferromagnet-Superconductor.
PDF Spin-polarized Shapiro steps and spin-precession-assisted multiple.
Spin-polarized multiple Andreev reflections in spin-split.
Asymmetric Andreev Reflection and Spin Hall Resonance at... - SpringerLink.
PDF Andreev Reflection and Subgap Transport Due to Electron-magnon.
Point-contact Andreev reflection in ferromagnet/superconductor.
Probing Spin Polarization with Andreev Reflection: A Theoretical.

Selective equal spin Andreev reflection at vortex core center in.

The process is highly spin-dependent - if only one spin band is occupied by the conduction electrons in the normal-state material (i.e. it is fully spin-polarized), Andreev reflection will be inhibited due to inability to form a pair in the superconductor and impossibility of single-particle transmission. In a ferromagnet or material where.

Spin-resolved Andreev levels and parity crossings in hybrid... - Nature.

The process is highly spin dependent - if only one spin band is occupied by the conduction electrons in the normal state material (ie - it is fully spin polarised), Andreev reflection will be inhibited due to inability to form a pair in the superconductor and impossibility of single particle transmission. This material combination allows spin degeneracy to be lifted without destroying superconductivity. We show that a spin-split Andreev level crossing the Fermi energy results in a quantum phase.

Spin polarized transport as measured by superconducting.

Spin-polarized Shapiro steps and spin-precession-assisted multiple Andreev reflection... Spin-polarized Shapiro steps and spin-precession-assisted multiple Andreev reflection. Physical Review B, 2014. Mikael Fogelström. W. Belzig. Download Download PDF. We study the transport properties of a voltage-biased contact between two spin-split superconductors separated by an insulating barrier of arbitrary transparency. At low transparency, the contribution of multiple Andreev reflections leads to a subharmonic gap structure that crucially depends on the amplitude and relative angle of the spin-splitting fields of each superconductor. A spin-up electron undergoes Andreev reflection over the length scale of the coherence length ξ inside the superconductor (1), and is reflected as a hole in the spin-down band. The hole is reflected back into the superconductor from the spin-active interface (2), where it picks up a phase shift θ s /2.

PDF Andreev experiments on superconductor/ferromagnet point contacts - CORE.

When the spatially in-homogenous spin polarized current reaches the NM/S interface, electrons enter the superconducting region. In the case of normal metal/SC interfaces, there are many mechanisms of electron transfer across JJ. In the following, we assume that the Andreev reflection process is the dominating mechanism of the electron transfer. Testify the helical spin texture of the edge states. By proper tuning of the band structures of the ferromagnetic layers, under the resonance bias voltage, the usual and novel local ARs of 100% can be all exhibited, resulting in fully spin-polarized pure spin-singlet superconductivity and. Superconductor (N/TS) junction, electrons with opposite spin polarization −n⃗ are completely decoupled from the MF and they cannot participate in Andreev reflections [Fig. 1(b)]. In other words, the MF selects electrons with certain spin polarization n⃗ to undergo equal-spin Andreev reflections. Therefore, we refer to this new phenomenon as.

Andreev Reflection - an overview | ScienceDirect Topics.

The current I resulting from the necessity to match spin-polarised current in the ferro-magnet with spin-lesscurrent in the superconductor. We calculate I using the tunnelling Hamiltonian method and the nonequilibrium (Keldysh) Green functions technique. It is shown that the inelastic magnon-assisted Andreev process would manifest itself as a. The process of electron reflecting back as a hole from the normal-superconductor interface and transferring a Cooper pair to the superconductor is termed Andreev reflection. Using the Blonder-Tinkham-Klapwijk ( Blonder et al., 1982) formalism, the conductance into the superconductor can be written in terms of elements of this scattering matrix as. Andreev reflection is a smart tool to investigate the spin polarization P of the current through point contacts between a superconductor and a ferromagnet. We compare different models to extract P from experimental data and investigate the dependence of P on different contact parameters. PACS: 72.25.Ba Spin polarized transport in metals.

Andreev Reflection in Ferromagnet/Superconductor/Ferromagnet.

We consider a hybrid quantum Hall-superconductor system, where a superconducting finger with oblique profile is wedged into a two-dimensional electron gas in the presence of a perpendicular magnetic field, as considered by Lee $\\textit{et al.}$, Nat. Phys. 13, 693 (2017). The electron gas is in the quantum Hall regime at filling factor $\ u=1$. Due to the Meissner effect, the perpendicular. INVESTIGATIONS OF CROSSED ANDREEV REFLECTION IN HYBRID SUPERCONDUCTOR-FERROMAGNET STRUCTURES BY MADALINA COLCI O'HARA Dipl. de Lie, University of Bucharest, 2000... 2.2.1 Spin Polarized Transport into a Nonmagnetic Metal 7 2.2.2 Magnetoresistance 14 2.2.3 Anisotropic Magnetoresistance 15. Andreev reflection spectroscopy of ferromagnet-superconductor (FS) junctions is an important probe of spin polarization. We theoretically investigate spin-polarized transport in FS junctions in the presence of Rashba and Dresselhaus interfacial spin-orbit fields and show that Andreev reflection can be controlled by changing the magnetization orientation. We predict a.

PDF Magnetoanisotropic Andreev Reflection in Ferromagnet-Superconductor.

Andreev reflection spectroscopy of ferromagnet/superconductor (FS) junctions is an important probe of spin polarization. We theoretically investigate. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Andreev reflection at the interface between a ferromagnet and a superconductor has become a foundation of a versatile new technique of measuring the spin polarization of magnetic materials. In this paper we will briefly outline a general theory of Andreev reflection for spin-polarized systems and arbitrary Fermi.

PDF Spin-polarized Shapiro steps and spin-precession-assisted multiple.

[2] Pannetier B and Courtois H 2000 Andreev reflection and proximity effect J. Low Temp. Phys. 118 599-615. Go to reference in article Crossref Google Scholar [3] Zhu J-X, Friedman B and Ting C S 1999 Spin-polarized quasiparticle transport in ferromagnet-d-wave-superconductor junctions with a {110} interface Phys. Rev. B 59 9558-63.. In the phase with two Majorana fermions, the superconductor can split Cooper pairs efficiently into electrons in two spatially separated leads due to Majorana-induced resonant-crossed Andreev reflections. The resulting currents in the leads are correlated and spin-polarized.

Spin-polarized multiple Andreev reflections in spin-split.

Illustration of spin-selective Andreev reflection in spin-polarized STM/scanning tunneling spectroscopy on a vortex center in a 2D topological superconductor, which is an effective chiral p-wave superconductor induced by the proximity effect at the surface of a 3D topological insulator.

Asymmetric Andreev Reflection and Spin Hall Resonance at... - SpringerLink.

One of the challenges facing condensed matter physics nowadays is to understand the electronic structure of high temperature superconductors. This dissertation compiles our contribution to the experimental information concerning this subject. Tunneling conductance spectroscopy a technique capable of probing the electronic density of states in hybrid structures was used to study the current and. We find crossed Andreev reflection (CAR) across the superconductor separating two qH edges. In integer fillings, we find a filling-independent CAR probability robust to changes in magnetic field and temperature, which we attribute to spin-orbit coupling in NbN allowing for Andreev reflection between spin-polarized edges.

PDF Andreev Reflection and Subgap Transport Due to Electron-magnon.

Point-contact andreev reflection ferromagnet superconductor ballistic nanojunctions bulk matrix element bulk material surface magnetization interface parameter co pb interface ferromagnet superconductor ballistic junction critical analysis tight-binding hamiltonians band structure measured differential conductance surface parameter magnetic.

Point-contact Andreev reflection in ferromagnet/superconductor.

May 06, 2010 · The hole spin accumulation and spin-polarized transport in ferromagnetic semiconductor (FS)/d-wave superconductor (SC)/FS tunnel junctions with {110} interfaces are studied by using four-component. Using the nonequilibrium Green's function method, we theoretically study the Andreev reflection(AR) in a four-terminal Aharonov-Bohm interferometer containing a coupled double quantum dot with the Rashba spin-orbit interaction (RSOI) and the coherent indirect coupling via two ferromagnetic leads. When two ferromagnetic electrodes are in the parallel configuration, the spin-up conductance is.

Probing Spin Polarization with Andreev Reflection: A Theoretical.

Sep 01, 1999 · We demonstrate that increasing the Fermi velocity mismatch in the Sm and S regions can lead to enhanced junction transparency in the presence of spin polarization. We find that the Andreev reflection amplitude at the superconducting gap energy is a robust measure of the spin polarization magnitude, being independent of the strengths of. Jul 12, 2016 · Majorana zero modes (MZMs) have been predicted to exist in the topological insulator (TI)/superconductor (SC) heterostructure. Recent spin polarized scanning tunneling microscope (STM) experiment$^{1}$ has observed spin-polarization dependence of the zero bias differential tunneling conductance at the center of vortex core, which may be attributed to the spin selective Andreev reflection, a. Here, the authors provide possible evidence for spin triplet Andreev reflection at the interface between a van der Waals ferromagnet Fe0.29TaS2 and a s-wave superconductor NbN.