Engineering and manipulating exciton wave packets

Article

关键词: DENSITY-FUNCTIONAL THEORY;    2-PHOTON ABSORPTION;    ENERGY-TRANSFER;    QUANTUM;    DYNAMICS;    EXCITATION;    THERMALIZATION;    DIFFUSION;    COUPLINGS;    COHERENCE;   

DOI  :  10.1103/PhysRevB.95.195423

来源: SCIE

【 摘 要 】

When a semiconductor absorbs light, the resulting electron-hole superposition amounts to a uncontrolled quantum ripple that eventually degenerates into diffusion. If the conformation of these excitonic superpositions could be engineered, though, they would constitute a new means of transporting information and energy. We show that properly designed laser pulses can be used to create such excitonic wave packets. They can be formed with a prescribed speed, direction, and spectral make-up that allows them to be selectively passed, rejected, or even dissociated using superlattices. Their coherence also provides a handle for manipulation using active, external controls. Energy and information can be conveniently processed and subsequently removed at a distant site by reversing the original procedure to produce a stimulated emission. The ability to create, manage, and remove structured excitons comprises the foundation for optoexcitonic circuits with application to a wide range of quantum information, energy, and light-flowtechnologies. The paradigm is demonstrated using both tight-binding and time-domain density functional theory simulations.

【 授权许可】

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