Detailed Study of microwave-activated c-Phase (MAP) gate in tunable 3D transmon two qubit system

Two-qubit microwave-activated c-Phase (MAP) gate was experimentally demonstrated earlier by Chow et al. [1]. Although MAP gate is an easily realizable entangling scheme between two fixed-frequency transmon qubits, it has not been extensively studied afterwards. In this study, we have investigated the performance of MAP gate in detail as an entangling gate, for the purpose of implementing it into simple quantum algorithms. Instead of using two fixed-transition frequency qubits, we used a tunable-frequency qubit in order to align the higher energy levels in situ to optimize the interaction between those levels. As a characterization of MAP gate, we will present the result of tomographic reconstruction of density matrices of various entangled states realized by MAP gate.

[1] J. Chow et al., New Journal of Physics 15, 115012 (2013)