Device and method for converting information between exciton valley polarization and photon topological state

Abstract

The invention discloses an information conversion device between exciton valley polarization and a photon topological state and a method thereof. A single-layer TMD material and a topological photonic crystal system are combined to form a heterojunction composite system, information conversion between the valley polarization information of excitons and the photonic topological state is achieved, the problem that the valley polarization information is too short in service life and difficult to directly utilize is solved, and the utilization requirement for the valley polarization information of electrons in the single-layer TMD material is lowered. The conversion system for the valley polarization information of the electrons and the photon topological state information can be used for integrating optoelectronic chips and serves as a platform for photoelectric information conversion; the two-dimensional topological photonic crystals of corresponding forbidden bands are selected according to different fluorescence emission wavelengths of different single-layer TMD materials, and adjustment can be completed by performing linear scaling on the structures of the two-dimensional topological photonic crystals, so that the design optimization time of devices of the same type is saved.

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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