Optical test method for electron spin diffusion transport kinetics based on pure phase liquid crystal spatial light modulator

Abstract

The invention relates to an optical test method for electron spin diffusion transport kinetics based on a pure phase liquid crystal spatial light modulator, wherein a one-dimensional pure phase liquid crystal spatial light modulator is combined with a time resolution pumping-detecting device, and the principle of an experimental device is indicated in the abstract figures. The one-dimensional pure phase liquid crystal spatial light modulator 7 is arranged in an overlapped area of a pumping light 2 and a detecting light 3, and is used for modulating circular polarization degrees of the cross sections of both the pumping light 2 and the detecting light 3 into the one-dimensional space period distribution. A modulation light field formed like this is imaged onto a sample 9 through an imaging lens 8. The modulated pumping light stimulates an electron spin polarization transient grating in the sample, and the modulated detecting light measures the decay kinetics of the electron spin polarization transient grating. An analytic model for the electron spin diffusion transport kinetics of the circular polarization one-dimensional sinusoidal and square wave type space period modulation light fields is provided. The method disclosed by the invention has the advantages of simple experimental device and operation, capability of testing the spin diffusion transport kinetics with the absorption saturation effect, and high sensitivity.

Description

technical field

[0001] The invention relates to a dynamic optical test method for electron spin diffusion transport. Its characteristic is that the polarization state distribution of the pump and probe beams is directly modulated by a pure phase liquid crystal spatial light modulator (POLCSLM), and a modulated light field with a one-dimensional periodic change in the degree of circular polarization is generated to respectively excite the transient electron spin grating and the probe beam. its decay kinetics. It has important application value in the field of measurement of semiconductor electron spin diffusion transport dynamics. Background technique

[0002] Ultra-large-scale semiconductor microelectronic integrated devices are currently encountering heat dissipation difficulties and limitations of quantum size effects. Therefore, the current CPU production cannot develop towards higher integration, but can only develop towards multiple CPUs. How to break through such lim...

Examples

example 1

[0009] Example 1 Generation of circular polarization one-dimensional sinusoidal space-period modulation light field and measurement of electron spin diffusion transport kinetics

[0010] Let the xy coordinates lie on the 1D-POLCSLM plane, the y axis is parallel to the long side of the pixel, and the x axis describes the one-dimensional position distribution of the pixel. The phase delay of each pixel is set by the controller to satisfy the following relationship:

[0011] φ ( i ) = 2 π Λ RMod ( i Λ ) - - - ( 1 )

[0012] In the formula, the function RMod() means that two numbers are divided, and the remainder is rounded to generate a sawtooth wave with a period of Λ and an ampl...

example 2

[0040] Example 2 Generation of circular polarization one-dimensional square wave space-period modulation light field and measurement of electron spin diffusion transport kinetics

[0041] When the one-dimensional spatial modulation period of the circular polarization degree of light is small, only a few pixels, such as Λ<10, the continuous approximate modulation described by equations (3) and (4) does not hold. The spin transport diffusion dynamics described in Example 1 no longer hold. Therefore, for small-period modulation, the example of the present invention develops a circular polarization one-dimensional square-wave space-period modulation optical field generation, and is used for the kinetic measurement of electron spin diffusion and transport.

[0042] Set the periodic phase of the spatial light modulator 7 as follows:

[0043] φ ( x ) = Σ q = ...

technical field

[0001] The invention relates to a dynamic optical test method for electron spin diffusion transport. Its characteristic is that the polarization state distribution of the pump and probe beams is directly modulated by a pure phase liquid crystal spatial light modulator (POLCSLM), and a modulated light field with a one-dimensional periodic change in the degree of circular polarization is generated to respectively excite the transient electron spin grating and the probe beam. its decay kinetics. It has important application value in the field of measurement of semiconductor electron spin diffusion transport dynamics. Background technique

[0002] Ultra-large-scale semiconductor microelectronic integrated devices are currently encountering heat dissipation difficulties and limitations of quantum size effects. Therefore, the current CPU production cannot develop towards higher integration, but can only develop towards multiple CPUs. How to break through such lim...

Examples

example 1

[0009] Example 1 Generation of circular polarization one-dimensional sinusoidal space-period modulation light field and measurement of electron spin diffusion transport kinetics

[0010] Let the xy coordinates lie on the 1D-POLCSLM plane, the y axis is parallel to the long side of the pixel, and the x axis describes the one-dimensional position distribution of the pixel. The phase delay of each pixel is set by the controller to satisfy the following relationship:

[0011] φ ( i ) = 2 π Λ RMod ( i Λ ) - - - ( 1 )

[0012] In the formula, the function RMod() means that two numbers are divided, and the remainder is rounded to generate a sawtooth wave with a period of Λ and an ampl...

example 2

[0040] Example 2 Generation of circular polarization one-dimensional square wave space-period modulation light field and measurement of electron spin diffusion transport kinetics

[0041] When the one-dimensional spatial modulation period of the circular polarization degree of light is small, only a few pixels, such as Λ<10, the continuous approximate modulation described by equations (3) and (4) does not hold. The spin transport diffusion dynamics described in Example 1 no longer hold. Therefore, for small-period modulation, the example of the present invention develops a circular polarization one-dimensional square-wave space-period modulation optical field generation, and is used for the kinetic measurement of electron spin diffusion and transport.

[0042] Set the periodic phase of the spatial light modulator 7 as follows:

[0043] φ ( x ) = Σ q = ...

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