Physical quantum process tomography of a CNOT gate

X.L. Zhang, Alexander Gill, L. Isenhower +2 more

J. L. O Brien

Kumel H. Kagalwala, Giovanni Di Giuseppe, Ayman F. Abouraddy +1 more

We describe an optical implementation of a CNOT gate in which the control qubit is the polarization of a single photon and the target qubit is the spatial parity of the same photon. The gate is implemented with a polarization- sensitive spatial light modulator. We characterize the operation of the gate using quantum process tomography and the spatial parity is analyzed with a modified Mach-Zehnder interferometer. We also demonstrate the CNOT-gate operation with arbitrary rotation of the target qubit and discuss the possibility of implementing multi-qubit CNOT gates using the same approach.

Robin Blume-Kohout

Taewan Noh, Gwanyeol Park, Soon-Gul Lee +2 more

We experimentally constructed an all-microwave scheme for the controlled-NOT (cNOT) gate between two superconducting transmon qubits in a three dimensional cavity. Our cNOT gate is based on the microwave-activated phase (MAP) gate, which requires an additional procedure to compensate the accumulated phases during the operation of the MAP gate. We applied Z-axis phase gates using microwave hyperbolic secant pulse on both qubits with adequate rotation angles systematically calibrated by separate measurements. We evaluated the gate performance of the constructed cNOT gate by performing two-qubit quantum process tomography (QPT). Finally, we present the experimental implementation of the Deutsch-Jozsa algorithm using the cNOT gate.

Norman Y. Yao, Chris R. Laumann, Alexey Vyacheslavovich Gorshkov +2 more