Method for independently regulating and controlling spin orbit coupling parameters of semiconductor quantum well

Abstract

The invention discloses a method for independently regulating and controlling spin orbit coupling parameters of a semiconductor quantum well and belongs to the technical field of semiconductor spintronics. The method comprises steps of selecting an asymmetrically doped semiconductor quantum well sample with a controllable metal gate; loading the sample into a piston sleeve type electric measurement high-voltage cavity, and applying pressure and a gate voltage to the sample; acquiring rashba and Dresselhaus spin orbit coupling parameters through anti-weak localization measurement, and realizingindependent regulation and control of the two spin orbit coupling parameters by adjusting the pressure and the grid voltage at the same time. The method for regulating and controlling the spin orbitcoupling strength parameters of the semiconductor quantum well is high in feasibility and can be carried out in situ, a new sample does not need to be prepared, independent regulation and control of the two parameters can be achieved respectively, and the regulation and control effect is remarkable.

Description

technical field [0001] The invention belongs to the technical field of semiconductor spin electronics, and in particular relates to a method for independently regulating the Rashba and Dresselhaus spin-orbit coupling parameters of semiconductor quantum wells. Background technique [0002] With the development of spintronics, the study of electron spin characteristics has become the most popular research direction in the field of condensed matter physics. The spin-orbit coupling with relativistic effect can closely link the spin and orbital motion of electrons, and then the spin-orbit coupling can be used to realize the full electrical control of electron spin and to prepare spin field effect transistors and qubits. The spin-orbit coupling interaction in the quantum well composed of semiconductor compounds is mainly composed of two parts: one is the Dresselhauss effect caused by the lack of bulk inversion symmetry center in the material, which includes two parts of the linear...

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Problems solved by technology

[0003] So far, people have made many attempts to control the spin-orbit coupling of semiconductor quantum wells: using the energy valley phase transition caused by the electric field-induced carrier distribution of GaAs can realize the electric field control of the spin-orbit coupling: but the control is discontinuous And it is difficult to achieve in other materials, and it is not universal; use the ratio adjustment of elements in the alloy to change the spin-orbit coupling of the material: but this regulation is not performed in situ and the prepared samples are introduced due to different components Defects and impurities, which complicate the problem and are not conducive to quantitative analysis; changing the quantum well width is an effective method to independently adjust the parameters of the Dresselhaus spin-orbit coupling: but this method needs to prepare different quantum well samples, the cost is high and the original method cannot be carried out. Bit regulation; Rashba and Dresselhaus spin-orbit coupling ratio can be adjusted by changing light and temperature: but this method needs to change the sample temperature to achieve regulation, and it cannot achieve independent regulation of the two spin-orbit coupling parameters; by changing the gate voltage The symmetry of the sample confinement layer structure is generally considered to be a feasible method to independently control the Rashba parameter α of the semiconductor quantum well: but this technique is limited to samples where α is dominant, because the change of electron density will also affect the Dresselhaus parameter γ; the pressure is in situ An effective way to control the spin-orbit coupling parameters: However, the change of the material band structure caused by pressure will cause simultaneous changes in α and γ, so the pressure itself cannot achieve independent control of the above two spin-orbit coupling parameters

[0004] In summary, the current control of the spin-orbit coupling strength of semiconductor quantum wells needs to be further improved

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