TY - JOUR
T1 - A new type of half-quantum circulation in a macroscopic polariton spinor ring condensate
AU - Liu, Gangqiang
AU - Snoke, David W.
AU - Daley, Andrew
AU - Pfeiffer, Loren N.
AU - West, Ken
PY - 2015/3/3
Y1 - 2015/3/3
N2 - We report the observation of coherent circulation in a macroscopic Bose-Einstein condensate of polaritons in a ring geometry. Because they are spinor condensates, half-quanta are allowed in where there is a phase rotation of Π in connection with a polarization vector rotation of Π around a closed path. This half-quantum behavior is clearly seen in the experimental observations of the polarization rotation around the ring. In our ring geometry, the half-quantum state that we see is one in which the handedness of the spin flips from one side of the ring to the other side in addition to the rotation of the linear polarization component; such a state is allowed in a ring geometry but will not occur in a simply connected geometry. This state is lower in energy than a half-quantum state with no change of the spin direction and corresponds to a superposition of two different elementary half-quantum states. The direction of circulation of the flow around the ring fluctuates randomly between clockwise and counterclockwise from one shot to the next; this fluctuation corresponds to spontaneous breaking of time-reversal symmetry in the system. This type of macroscopic polariton ring condensate allows for the possibility of direct control of the circulation to excite higher quantized states and the creation of Josephson junction tunneling barriers.
AB - We report the observation of coherent circulation in a macroscopic Bose-Einstein condensate of polaritons in a ring geometry. Because they are spinor condensates, half-quanta are allowed in where there is a phase rotation of Π in connection with a polarization vector rotation of Π around a closed path. This half-quantum behavior is clearly seen in the experimental observations of the polarization rotation around the ring. In our ring geometry, the half-quantum state that we see is one in which the handedness of the spin flips from one side of the ring to the other side in addition to the rotation of the linear polarization component; such a state is allowed in a ring geometry but will not occur in a simply connected geometry. This state is lower in energy than a half-quantum state with no change of the spin direction and corresponds to a superposition of two different elementary half-quantum states. The direction of circulation of the flow around the ring fluctuates randomly between clockwise and counterclockwise from one shot to the next; this fluctuation corresponds to spontaneous breaking of time-reversal symmetry in the system. This type of macroscopic polariton ring condensate allows for the possibility of direct control of the circulation to excite higher quantized states and the creation of Josephson junction tunneling barriers.
KW - polariton condensates
KW - quantized circulation
KW - ring condensates
KW - spinor condensates
UR - http://www.scopus.com/inward/record.url?scp=84924368602&partnerID=8YFLogxK
UR - http://www.pnas.org/
U2 - 10.1073/pnas.1424549112
DO - 10.1073/pnas.1424549112
M3 - Article
AN - SCOPUS:84924368602
SN - 0027-8424
VL - 112
SP - 2676
EP - 2681
JO - Proceedings of the National Academy of Sciences
JF - Proceedings of the National Academy of Sciences
IS - 9
ER -