Direct measurement of the concurrence of hybrid entangled state based on parity check measurements<xref rid="cpb_28_1_010301fn1" ref-type="fn">*</xref> <fn id="cpb_28_1_010301fn1"> <label>*</label> <p>Project supported by the National Natural Science Foundation of China (Grant Nos. 11474168 and 11747161) and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.</p> </fn>

Direct measurement of the concurrence of hybrid entangled state based on parity check measurements* *

Project supported by the National Natural Science Foundation of China (Grant Nos. 11474168 and 11747161) and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China.

Zhang Man¹, Zhou Lan², Zhong Wei^{1, 3}, Sheng Yu-Bo^{1, 3, †}

Schematic diagram of the PCM. The function of the PCM is to distinguish the states |HV⟩ and |VH⟩ from |HH⟩ and |VV⟩. The PBS can transmit the horizontally polarized photon (|H⟩) and reflect the vertically polarized photon (|V⟩). HWP45° is a half-wave plate placed in 45°, whose function is |V⟩ → |H⟩ and |H⟩ → |V⟩. A photon in a_c mode introduces +θ on the coherent probe beam |α⟩_p, while a photon in b_c introduces −θ on |α⟩_p. |X⟩⟨X| represents an X quadrature homodyne measurement.