Quantum Optimal Control Of The Electron Excitation And Transfer In GaAs Double Quantum Dots

With the development of quantum theory and experimental technique, scientists have always been expecting to control quantum systems’dy-namic behaviour. One of the most powerful laboratory facilities is by means of laser pulse. Since the 1980s, femtosecond laser pulse and pulse shaping method have been used to overcome difficulties of intramolecu-lar vibrational relaxation. Thus, control of quantum processes and sys-tems, such as selective breaking of chemical bonds, molecular alignment, aromatic molecule electric current and high-harmonic generation, can be utilized. Quantum optimal control theory(QOCT) can be used to design theoretically the laser pulse to transfer an initial state of quantum system to a given target state. On the other hand, in order to make qubits and finally build quantum conputers,semicondutor quantum dot(QDs) struc-tures have attracted great interest in terms of coherent control of electron spin and charge states. The main advantage of QDs arise from their tun-ability of shape, size and the number of confined electrons.In this thesis, we employed QOCT to simulate and controlGaAs semi-conductor quantum dot described by effecive mass approximation and parabolic confinement potential. Specifically, the one dimensional and two dimensional model were adopted. We calculated the electronic prop-erties of ground state and excited states. To control the electron from the ground state to various level of excited states, optimal laser pulse was de-signed in theory and iterative algorithm was used to solve a set of control equations. We analyzed different parameters of the laser pulse and the yield of the control target. In the control of electron excitation and trans-fer, QOCT has some advantages over other control strategies. The control time is much shorter and within the decoherence time of quantum dot. The control cycle is finished in tens of picoseconds. As the pulse shap-ing and generation technology advances, laser pulse in THz frequency can be implemented in practice. We provided theortical guidance for optimal pulse shaping and designment in laboratory.