We report a new method for injecting angular momentum in a polariton superfluid. Rather than stirring, such as what is done in atomic BECs, we resonantly inject a ring-shaped rotating superfluid in a planar semiconductor cavity. The resonant injection avoids any significant exciton populations and ensures a high level of control in the system. A Spatial Light Modulator is used to create a Laguerre-Gaussian laser beam that pumps the system and creates a rotating polariton population. By using a ℓ = 8 Laguerre-Gaussian mode we have studied the steady-state condition for observing the nucleation of angular momentum in freely propagating polaritons at the center. We find that, likely due to the fixed border conditions, the angular momentum in weak cavity disorder areas does not spontaneously nucleates at the center, and we observe a single ℓ = 8 vortex. For larger cavity disorder vortex-antivortex pairs can nucleate and we present numerical simulations that explain the role of this disorder to observe such a nucleation.

Date Published: 8 February 2015
PDF: 10 pages
Proc. SPIE 9370, Quantum Sensing and Nanophotonic Devices XII, 93702R (8 February 2015); doi: 10.1117/12.2076013

Published in SPIE Proceedings Vol. 9370:
Quantum Sensing and Nanophotonic Devices XII
Manijeh Razeghi; Eric Tournié; Gail J. Brown, Editor(s)