In this scheme, two quantum oscillators in a planar radio frequency ion trap are coupled by the trap electrodes. The ions motional states encode the quantum bits （qubits）, and a swap gate could be achieved. Under different conditions of the experiments, the intensity of the coupling between＇two quantum oscillators and the dissipation of the system are calculated. We compute fidelities for a quantum swap gate and discuss experimental issues.
A femtosecond optical parametric oscillator synchronously pumped by a Ti:Sapphire oscillator is reported.By the cavity length tuning,the signal wavelength is continuously tuned from 1000 to 1200 nm.The average output power of 32 mW is obtained at 1053 nm.The pulse width is measured to be 342 fs by intensity autocorrelation method.In addition,we observed bichromatic emission during the cavity length tuning process.
Two extended-cavity diode lasers at 780 nm which are longtime frequency-stabilized to Rb^（87） saturated absorption signals are reported.A high-performance frequency-locking circuit module using a first-harmonic detection technique is designed and achieved.Two lasers are continuously frequency-stabilized for over 100 h in conventional laboratory condition.The Allan standard deviation of either laser is estimated to be 1.3×10^（-11） at an integration time of 25 s.The system environment temperature drift is demonstrated to be the main factor affecting long-term stability of the stabilized lasers based on our correlation study between beat frequency and system environment temperature.
The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.
