Theoretical investigation of the applicability of the Meservey-Tedrow technique to the surface states of topological insulators

Abstract

The spin polarization of topological surface states is of high interest for possible applications in spintronics. At present, the only technique capable to measure the surface state spin texture is spin and angle resolved photoemission spectroscopy (SARPES). However, values reported by SARPES differed strongly. An established technique to measure the spin polarization of ferromagnetic materials is the so-called Meservey-Tedrow technique, which is based on spin dependent tunneling from a superconducting electrode to a ferromagnet. Here, we theoretically investigate how the Meservey-Tedrow technique can be adapted to topological insulators. We demonstrate that with a specific device geometry it is possible to determine the in-plane component of the spin polarization of topological surface states. More complex device geometries can access the full momentum dependence of the spin polarization. We also show that it is possible to extract the spin-flip scattering rate of surface electrons with the same devices.

arXiv comment10 pages, 9 figures

References in corpus (22)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators in Three Dimensions
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Model Hamiltonian for Topological Insulators
• The Quantum Spin Hall Effect: Theory and Experiment
• Manipulation of Majorana fermion, Andreev reflection and Josephson current on topological insulators
• A conductive topological insulator with colossal spin Hall effect for ultra-low power spin-orbit-torque switching
• Room temperature spin-orbit torque switching induced by a topological insulator
• Spin Polarization and Transport of Surface States in the Topological Insulators Bi2Se3 and Bi2Te3 from First Principles
• Inverse Spin-Galvanic Effect in a Topological-Insulator/Ferromagnet Interface
• Quintuple-layer epitaxy of high-quality Bi2Se3 thin films for topological insulator
• Electronic Structure of the Topological Insulator Bi2Se3 Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization
• Direct Measurement of the Out-of-Plane Spin Texture in the Dirac Cone Surface State of a Topological Insulator
• Switching spin and charge between edge states in topological insulator constrictions
• Widespread spin polarization effects in photoemission from topological insulators
• Spin Polarization of Photoelectrons from Topological Insulators
• Photoemission of Bi${}_2$Se${}_3$ with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?
• Surface spectral function in the superconducting state of a topological insulator
• Enhanced transport length of spin-helical Dirac fermions in disordered 3D topological insulators
• Pure spin current devices based on ferromagnetic topological insulators
• Tunneling magnetoresistance devices based on topological insulators: Ferromagnet/insulator/topological-insulator junctions employing Bi${}_2$Se${}_3$

Cited by in corpus (1)

• Determination of Out-of-plane Spin Polarization of Topological Surface States by Spin Hall Effect Tunneling Spectroscopy