QUANTUM-ENTANGLEMENT VERIFICATION METHOD, QUANTUM-ENTANGLEMENT VERIFICATION DEVICE, AND QUANTUM-ENTANGLEMENT VERIFICATION PROGRAM

摘要

PPROBLEM TO BE SOLVED: To provide a technology for verifying a quantum entanglement conditions which are shared by n quanta. PSOLUTION: A symbol ¾SB/SB representing an inter-n-quantum state (n3) used in a projector is divided into two groups by means of possible 2SPn-1/SP-1 kinds of methods, and entanglement index is computed for each divided group. The classes S (kSB1/SB, ..., kSBm/SB) of entanglements to be distinguished are set from values kSBt/SBwhich are lower than the entanglement indexes of the divided groups (1t2SPn-1/SP-1 and m=2SPn-1/SP-1). The maximum fidelity is found by calculating equation c=maxSBES(k1, ..., km)/SBSB/SB¾¾SB/SB (whereSBE/SBrepresents a set symbol). An entanglement verification operator W=cI-¾SB/SBSB/SB¾ is measured with respect to the inter-n-quantum state to be measured to compute the expectation value Tr(W)SBexp/SBof Tr(W), (I represents unit matrix). Whether the Tr(W)SBexp/SBis larger than 0 is determined, to verify the quantum entanglement state of the quantum state . PCOPYRIGHT: (C)2007,JPO&INPIT