An information conversion device and method between exciton valley polarization and photon topological state

Abstract

The invention discloses an information conversion device between exciton valley polarization and photon topological state and a method thereof. The invention combines the single-layer TMD material with the topological photonic crystal system to form a heterojunction composite system, which realizes the information conversion between the valley polarization information of the excitons and the photon topological state, and solves the problem that the valley polarization information has too short a lifespan. The problem of direct utilization reduces the requirement for the use of valley polarization information of electrons in single-layer TMD materials; the conversion system for valley polarization information of electrons and photon topological state information proposed by the present invention can be used for integrated optoelectronic chips, As a platform for photoelectric information conversion; according to the different fluorescence emission wavelengths of different single-layer TMD materials, select the two-dimensional topological photonic crystal with the corresponding band gap, and linearly scale the structure of the two-dimensional topological photonic crystal to complete the adjustment, saving The design optimization time of the same type of device is reduced.

Description

technical field [0001] The invention relates to valley polarization information conversion technology, in particular to an information conversion device and a conversion method between exciton valley polarization and photon topological state. Background technique [0002] Similar to spintronics, which uses the spin degree of freedom of electrons to encode information, valleytronics mainly utilizes the energy valley degree of freedom of transition metal chalcogenides (TMD) in the reciprocal space to realize information encoding and processing. The single-layer TMD material has a direct band gap composed of energy degenerate energy valleys (K and K') in the inverted space, and the selection rule based on the energy valley determines that when left-handed or right-handed circularly polarized light is incident, The electrons in the K or K' valley are selectively excited and then jump to the conduction band, forming valley-polarized excitons with the holes, and then the electrons...

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Problems solved by technology

In addition, due to the limitation of micro-nano processing precision, defects and impurities in the device will cause strong backscattering of light, which will seriously affect the performance of the device.

On the other hand, photonic crystal line-defect waveguides cannot adapt to large-angle bending, which also limits its application in optical information processing devices.

[0004] The energy valley degree of freedom of electrons in two-dimensional TMD materials can be used for information encoding and information processing, but the lifetime of this valley-polarized excitons is too short, which is not conducive to the transmission and processing of valley-polarized information

Valley polarized excitons will emit circularly polarized photons, which can be coupled into an optical system to achieve information conversion, but the coupling of circularly polarized light by ordinary optical systems is difficult and inefficient

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