Quantum estimation of detection efficiency with no-knowledge quantum feedback<xref rid="cpb_27_6_060303_fn1" ref-type="fn">*</xref> <fn id="cpb_27_6_060303_fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant No. 11747008) and the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2016GXNSFBA380227).</p> </fn>

Quantum estimation of detection efficiency with no-knowledge quantum feedback* *

Project supported by the National Natural Science Foundation of China (Grant No. 11747008) and the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2016GXNSFBA380227).

Xie Dong^†, Xu Chunling

(color online) Diagram of simultaneous and independent estimation δη² + δω² changing with detection efficiency η, given by the same probes. Here, we calculate the precision with an average of one probe. It shows that the simultaneous estimation performs better than the independent estimation.