Noiseless linear amplification for the single-photon entanglement of arbitrary polarization–time-bin qudit<xref rid="cpb_28_1_010302fn1" ref-type="fn">*</xref> <fn id="cpb_28_1_010302fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11474168 and 11747161), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, and the China Postdoctoral Science Foundation (Grant No. 2018M642293).</p> </fn>

Noiseless linear amplification for the single-photon entanglement of arbitrary polarization–time-bin qudit* *

Project supported by the National Natural Science Foundation of China (Grant Nos. 11474168 and 11747161), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, and the China Postdoctoral Science Foundation (Grant No. 2018M642293).

Chen Ling-Quan^{1, 2}, Sheng Yu-Bo^{3, 4}, Zhou Lan^{1, 3, †}

The amplification factor g as a function of the transmittance t with different initial fidelity F = 0.2, 0.4, 0.6, and 0.8. When t = 0.5, the four curves intersect at one point of g = 1, which indicates that the fidelity of the distilled new mixed state equals that of the initial mixed state. The amplification only occurs under t < 1/2.