Title :
Ultrafast Manipulation of a Double Quantum-Dot Charge Qubit Using Lyapunov-Based Control Method
Author :
Shuang Cong ; Ming-Yong Gao ; Gang Cao ; Guang-Can Guo ; Guo-Ping Guo
Author_Institution :
Dept. of Autom., Univ. of Sci. & Technol. of China, Hefei, China
Abstract :
For a two-level double quantum-dot (DQD) system, we proposed an alternative ultrafast manipulation approach, Lyapunov-based control method, to transfer the charge qubit from the initial charge state |R) to the target charge state |L) on the picosecond scale. Better control performance is obtained compared with that via Landau-Zener-Stu̅ckberge-Majorana interference, and the designed control fields can be implemented in the actual experiment facility. The control process is composed of three parts: first, a slope pulse takes the system from a positive detuning adiabatically to the anticrossing point, which corresponds to the resonance state of the system; then, a Lyapunov-based control pulse drives the charge qubit transfer nonadiabatically; finally, another slope pulse takes the system away from the anticrossing point to keep the system stable. The charge qubit transfer performance and the function of Lyapunov-based control pulse were studied under different control parameters. Simulation results showed that the designed Lyapunov-based control pulse has a rise time ~20 ps, which is in the scope of the Tektronix AWG70000A series arbitrary waveform generator and results in a significant probability ~96% for the transition from the initial charge state |R) to the target charge state |L). The fidelity of the control process designed can achieve ~94%. This is the first result directly applicable for a DQD charge qubit transfer using the Lyapunov-based control method.
Keywords :
Lyapunov methods; quantum computing; quantum optics; semiconductor quantum dots; Lyapunov-based control method; Lyapunov-based control pulse; Tektronix AWG70000A series arbitrary waveform generator; anticrossing point; double quantum-dot charge qubit transfer; initial charge state; picosecond scale; resonance state; target charge state; two-level double quantum-dot system; Control systems; Energy states; Interference; Logic gates; Lyapunov methods; Process control; Quantum dots; Double quantum dot (DQD); LZSM interference; double quantum dot (DQD); numerical simulations; quantum Lyapunov control method;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2015.2440783