Group-velocity-controlled and gate-tunable directional excitation of polaritons in graphene-boron nitride heterostructures

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...

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Bibliographic Details
Main Authors: Jiang, Yuyu, Lin, Xiao, Low, Tony, Zhang, Baile, Chen, Hongsheng
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2019
Subjects:
Online Access:https://hdl.handle.net/10356/84565
http://hdl.handle.net/10220/50422
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Institution: Nanyang Technological University
Language: English
Description
Summary: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 (hBN) 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‐hBN heterostructures thus present a promising platform toward nano‐photonic circuits and nano‐devices with electrically reconfigurable functionalities.