Observation of half-quantum vortices in an exciton-polariton condensate.
Singly quantized vortices have already been observed in many systems, including the superfluid helium, Bose-Einstein condensates of dilute atomic gases, and condensates of exciton-polaritons in the solid state. Two-dimensional superfluids carrying spin are expected to demonstrate a different type of elementary excitations referred to as half-quantum vortices, characterized by a pi rotation of the phase and a pi rotation of the polarization vector when circumventing the vortex core. We detect half-quantum vortices in an exciton-polariton condensate by means of polarization-resolved interferometry, real-space spectroscopy, and phase imaging. Half-quantum vortices coexist with single-quantum vortices in our sample.
Lagoudakis
K G
KG
Institut de Photique et d'Electronique Quantique (IPEQ), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland. konstantinos.lagoudakis@epfl.ch
Ostatnický
T
T
Kavokin
A V
AV
Rubo
Y G
YG
André
R
R
Deveaud-Plédran
B
B