Method of distinguishing photoinduced reverse spinning Hall currents of surface state and bulk state of Bi2Se3

Abstract

The invention relates to a method of distinguishing photoinduced reverse spinning Hall currents of surface state and bulk state of Bi2Se3. The method of distinguishing photoinduced reverse spinning Hall currents of surface state and bulk state of Bi2Se3 includes the steps: growing a topological insulator Bi2Se3 on the crystal face (111) of a strontium titanate substrate; using Gaussian distribution circular polarization laser to excite the photoinduced reverse spinning Hall effect currents of surface state and bulk state of the topological insulator Bi2Se3 in the vertical incidence situation,and measuring the photoinduced reverse spinning Hall effect current when the light spot position moves on a vertical bisector of two electrode connection lines; and finally, establishing quantitativefitting models which are used for distinguishing the photoinduced reverse spinning Hall currents of surface state and bulk state of the topological insulator Bi2Se3, performing model fitting, and obtaining the photoinduced reverse spinning Hall currents of the surface state and the bulk state. The method of distinguishing photoinduced reverse spinning Hall currents of surface state and bulk stateof Bi2Se3 has the advantages of being very simple and practicable, being low in cost, being conductive for popularization and application in the future, and being accurate in the obtained results.

Description

technical field [0001] The invention belongs to the field of spin electronics, and in particular relates to a method for distinguishing Bi2Se3 surface state and bulk state photoinduced inverse spin Hall current. Background technique [0002] Topological insulators have attracted widespread attention due to their exotic physical properties and potential applications in quantum computing, spintronics and other fields. Bi2Se3 is a typical representative of the topological insulator family because of its wide band gap and single pair of Dirac cones. However, due to the presence of more Se vacancies in Bi2Se3 materials and the influence of gas impurities in the growth environment, Bi2Se3 usually behaves as n-type, that is, the bulk state is not insulating, but has a large bulk conductance. This makes it difficult for people to obtain the current signal caused solely by the surface state, and the measured signal is often a mixed signal of the bulk state and the surface state. Th...

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Problems solved by technology

However, these two methods cannot obtain information about the electrical correlation of the surface states of topological insulators

Photoinduced inverse spin Hall current is an effective method to study the spin Hall effect and spin-related electrical properties of materials. However, for topological insulator Bi2Se3, the measured photoinduced inverse spin Hall current is often is a superposition of bulk and surface states, it is difficult to distinguish them

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