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Demonstration of a quantum controlled-NOT gate in the telecom band



Jun Chen, Joseph B. Altepeter, Milja Medic, Fook L. Kim, Burc Gokden, Robert Hadfield, Sae Woo Nam, Prem Kumar


We present the first quantum controlled-NOT (CNOT) gate realized using a fiber-based indistinguishable photon-pair source in the 1.55 υm telecommunications band. Using this free-space CNOT gate, all four Bell states are produced and fully characterized by performing quantum-state tomography, demonstrating the gate's unambiguous entangling capability and high fidelity. Telecom-band operation makes this CNOT gate particularly suitable for quantum-information-processing tasks that are at the interface of quantum communication and linear optical quantum computing.
Physical Review Letters


quantum compting, CNOT, linear optics, superconducting detectors, SSPD


Chen, J. , Altepeter, J. , Medic, M. , Kim, F. , Gokden, B. , Hadfield, R. , Nam, S. and Kumar, P. (2008), Demonstration of a quantum controlled-NOT gate in the telecom band, Physical Review Letters, [online], (Accessed April 13, 2024)
Created April 3, 2008, Updated October 12, 2021