Experimental Demonstration of Spontaneous Chirality in a Nonlinear Microresonator.
Chirality is an asymmetric property widely found in nature. Here, we propose and demonstrate experimentally the spontaneous emergence of chirality in an on-chip ultrahigh-Q whispering-gallery microresonator, without broken parity or time-reversal symmetry. This counterintuitive effect arises due to the inherent Kerr-nonlinearity-modulated coupling between clockwise and counterclockwise propagating waves. Above an input threshold of a few hundred microwatts, the initial chiral symmetry is broken spontaneously, and the counterpropagating output ratio exceeds 20∶1 with bidirectional inputs. The spontaneous chirality in an on-chip microresonator holds great potential in studies of fundamental physics and applied photonic devices.
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
Qi-Tao
QT
Cao
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
Heming
H
Wang
Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Chun-Hua
CH
Dong
Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, People's Republic of China.
Hui
H
Jing
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
Rui-Shan
RS
Liu
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.
Xi
X
Chen
Department of Engineering Science and Physics, College of Staten Island, CUNY, Staten Island, New York 10314, USA.|The Graduate Center, CUNY, New York, New York 10016, USA.
Li
L
Ge
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.|Collaborative Innovation Center of Extreme Optics, Taiyuan 030006, Shanxi, People's Republic of China.
Qihuang
Q
Gong
State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University; Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China.|Collaborative Innovation Center of Extreme Optics, Taiyuan 030006, Shanxi, People's Republic of China.
Yun-Feng
YF
Xiao