Spin-resolved Purcell effect in a quantum dot microcavity system.
We demonstrate the spin selective coupling of the exciton state with cavity mode in a single quantum dot (QD)-micropillar cavity system. By tuning an external magnetic field, each spin polarized exciton state can be selectively coupled with the cavity mode due to the Zeeman effect. A significant enhancement of spontaneous emission rate of each spin state is achieved, giving rise to a tunable circular polarization degree from -90% to 93%. A four-level rate equation model is developed, and it agrees well with our experimental data. In addition, the coupling between photon mode and each exciton spin state is also achieved by varying temperature, demonstrating the full manipulation over the spin states in the QD-cavity system. Our results pave the way for the realization of future quantum light sources and the quantum information processing applications.
State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Department of Physics, Fudan University, Shanghai 200433, China.
Qijun
Q
Ren
Jian
J
Lu
H H
HH
Tan
Shan
S
Wu
Liaoxin
L
Sun
Weihang
W
Zhou
Wei
W
Xie
Zheng
Z
Sun
Yongyuan
Y
Zhu
C
C
Jagadish
S C
SC
Shen
Zhanghai
Z
Chen