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Group‐Velocity‐Controlled and Gate‐Tunable Directional Excitation of Polaritons in Graphene‐Boron Nitride Heterostructures
Author(s) -
Jiang Yuyu,
Lin Xiao,
Low Tony,
Zhang Baile,
Chen Hongsheng
Publication year - 2018
Publication title -
laser and photonics reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.778
H-Index - 116
eISSN - 1863-8899
pISSN - 1863-8880
DOI - 10.1002/lpor.201800049
Subject(s) - graphene , materials science , group velocity , optoelectronics , polariton , photonics , boron nitride , heterojunction , excitation , plasmon , nanotechnology , optics , physics , quantum mechanics
Abstract A fundamental building block in nano‐photonics is the ability to directionally excite highly squeezed optical mode dynamically, particularly with an electrical bias. Such capabilities would enable the active manipulation of light propagation for information processing and transfer. However, when the optical source is built‐in, it remains challenging to steer the excitation directionality in a flexible way. Here, a mechanism is revealed for tunable directional excitation of highly squeezed polaritons in graphene‐hexagonal boron nitride ( h BN) heterostructures. The effect relies on controlling the sign of the group velocity of the coupled plasmon‐phonon polaritons, which can be flipped by simply tuning the chemical potential of graphene (through electrostatic gating) in the heterostructures. Graphene‐ h BN heterostructures thus present a promising platform toward nano‐photonic circuits and nano‐devices with electrically reconfigurable functionalities.