Nanoscale Optical Addressing of Valley Pseudospins through Transverse Optical Spin

Nanoscale Optical Addressing of Valley Pseudospins through Transverse Optical Spin

Gong, S. (TU Delft QN/Kuipers Lab; Korea University; Kavli institute of nanoscience Delft)
Komen, I. (TU Delft QN/Kuipers Lab; Kavli institute of nanoscience Delft)
Alpeggiani, F. (TU Delft QN/Kuipers Lab; Kavli institute of nanoscience Delft)
Kuipers, L. (TU Delft QN/Quantum Nanoscience; Kavli institute of nanoscience Delft)

QN/Quantum Nanoscience

2020

Valley pseudospin has emerged as a good quantum number to encode information, analogous to spin in spintronics. Two-dimensional transition metal dichalcogenides (2D TMDCs) recently attracted enormous attention for their easy access to the valley pseudospin through valley-dependent optical transitions. Different ways have been reported to read out the valley pseudospin state. For practical applications, on-chip access to and manipulation of valley pseudospins is paramount, not only to read out but especially to initiate the valley pseudospin state. Here, we experimentally demonstrate the selective on-chip, optical near-field initiation of valley pseudospins at room temperature. We exploit a nanowire optical waveguide, such that the local transverse optical spin of its guided modes selectively excites a specific valley pseudospin. Furthermore, spin-momentum locking of the transverse optical spin enables us to flip valley pseudospins with the opposite propagation direction. Thus, we open up ways to realize integrated hybrid opto-valleytronic devices.

TMDC materials
WS
ZnO nanowires
spin-momentum locking
transverse optical spin
valleytronics

http://resolver.tudelft.nl/uuid:14fdf026-23f1-4756-aaf9-e5ce407c7b69

https://doi.org/10.1021/acs.nanolett.0c01173

1530-6984

Nano Letters: a journal dedicated to nanoscience and nanotechnology, 20 (6), 4410-4415

Institutional Repository

journal article

© 2020 S. Gong, I. Komen, F. Alpeggiani, L. Kuipers