We study numerically the dynamics of two-qubit gates with superconducting charge qubits. The exact ratio of $E_J$ to $E_L$ and the corresponding operation time are calculated in order to implement two-qubit gates. We investigate the effect of finite rise and fall times of pulses in realization of two-qubit gates. It is found that the error in implementing two-qubit gates grows quadratically in rise and fall times of pulses.

• Received 22 May 2001

DOI:https://doi.org/10.1103/PhysRevB.65.144526