An in-plane photoelectric effect in two-dimensional electron systems for terahertz detection

Wladislaw Michailow; Peter Spencer; Nikita W. Almond; Stephen J. Kindness; Robert Wallis; Thomas A. Mitchell; Riccardo Degl'Innocenti; Sergey A. Mikhailov; Harvey E. Beere; David A. Ritchie

arXiv · 2011.04177

An in-plane photoelectric effect in two-dimensional electron systems for terahertz detection

Wladislaw Michailow·Peter Spencer·Nikita W. Almond·Stephen J. Kindness·Robert Wallis·Thomas A. Mitchell·Riccardo Degl'Innocenti·Sergey A. Mikhailov·Harvey E. Beere·David A. Ritchie

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Abstract

The photoelectric effect consists in the photoexcitation of electrons above a potential barrier at a material interface and is exploited for photodetection over a wide frequency range. This three-dimensional process has an inherent inefficiency: photoexcited electrons gain momenta predominantly parallel to the interface, while to leave the material they have to move perpendicular to it. Here, we report on the discovery of an in-plane photoelectric effect occurring within a two-dimensional electron gas. In this purely quantum-mechanical, scattering-free process, photo-electron momenta are perfectly aligned with the desired direction of motion. The "work function" is artificially created and tunable in-situ. The phenomenon is utilized to build a direct terahertz detector, which yields a giant zero-bias photoresponse that exceeds the predictions by known mechanisms by more than 10-fold. This new aspect of light-matter interaction in two-dimensional systems paves the way towards a new class of highly efficient photodetectors covering the entire terahertz range.

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Wladislaw Michailow, Peter Spencer, Nikita W. Almond, Stephen J. Kindness, Robert Wallis, Thomas A. Mitchell, Riccardo Degl'Innocenti, Sergey A. Mikhailov, Harvey E. Beere, David A. Ritchie. 2020-11-09. An in-plane photoelectric effect in two-dimensional electron systems for terahertz detection. https://arxiv.org/abs/2011.04177

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