We demonstrate unconditional quantum-noise suppression in a collective spin system via feedback control based on quantum nondemolition measurement. We perform shot-noise limited collective spin measurements on an ensemble of 3.7 X 10(5) laser-cooled Yb-171 atoms in their spin-1/2 ground states. Correlation between two sequential quantum nondemolition measurements indicates -0.80(-0.12)(+0.11) dB quantum-noise suppression in a conditional manner. Our feedback control successfully converts the conditional quantum-noise suppression into the unconditional one without significant loss of the noise reduction level. DOI: 10.1103/PhysRevLett.110.163602
机构:
College of Computer Science, Shaanxi Normal University, Xi'an 710062, ChinaCollege of Computer Science, Shaanxi Normal University, Xi'an 710062, China
Xi, Zhengjun
Li, Yongming
论文数: 0引用数: 0
h-index: 0
机构:
College of Computer Science, Shaanxi Normal University, Xi'an 710062, ChinaCollege of Computer Science, Shaanxi Normal University, Xi'an 710062, China
Li, Yongming
Jisuanji Yanjiu yu Fazhan/Computer Research and Development,
2011,
48
(11):
: 2155
-
2160