Highly Tunable Charge–Spin Conversion in Topological Insulator Cr_0.08-(Bi_0.37Sb_0.63)_1.92Te₃ via Ferroelectric Polarization

Abstract

Topological insulators possess strong spin−orbit coupling, which potentially presents efficient charge−spin interconversion. The effective manipulation of this conversion plays a central role in spin-based device applications and is attracting increasing attention nowadays. In this study, by constructing a multifunctional hybrid device Cr-BST/Py/PMN-PT and applying spin-torque ferromagnetic resonance measurement, continuously controllable charge−spin conversion efficiency and even the enhancement of its value up to about 450% are realized via regulation of the ferroelectric polarization in the topological insulator Cr-BST. The band structure of Cr-BST characterized by angle-resolved photoelectron spectroscopy measurement presents an apparent Dirac-like state located at the large band gap of the bulk state near the Fermi level, which indicates a surface statedominated contribution to the charge−spin conversion. Further investigation via density functional theory on the electronic structure of BST verifies that the controllable conversion efficiency dominantly originates from the evolution of the band structure under strain modulation. These findings demonstrate TIs as one of the promising materials for the charge−spin interconversion and its regulation, which are instructive for low-dissipation spintronics devices.

Helicity-dependent photoconductance of the edge states in the topological insulator Bi2Te3

“…Three-dimensional (3D) topological insulators (TIs), as a new quantum phase of mater, are characterized by gapless spin-textured surface states that reside within the bulk band gap. [1][2][3][4][5][6] The electrons on the surface states of 3D TIs behave as Dirac fermions bearing a characteristic called spinmomentum locking. The unique properties of topological surface states make them promising in the field of spintronic devices and quantum computing.…”

Data Acquisition System Based on the Bluesky Suite in the Shanghai Synchrotron Radiation Facility

“…So far, data acquisition systems based on SSRF Bluesky suite have been developed and applied at the BL07U beamline and the BL16U1 beamline of SSRF. In particular, the BL07U data acquisition system has been highly evaluated after it opened to users [16,17].…”