论文标题
Rashba控制的两电子旋转量子台作为量子计算机的构建块
Rashba controlled two-electron spin-charge qubits as building blocks of a quantum computer
论文作者
论文摘要
最近提出，由外部磁场控制的自旋敏感电荷振荡是作为Quartum量子点中的两电子旋转荷威丝分子定义为Qubits转换的机制。该论文通过包括Rashba型自旋轨道耦合的影响来扩展这一想法。理论上通过将系统映射到8个低能量状态的分析有效的哈密顿量来研究，从理论上研究了这个问题，其中包括每个点对角线的单线和三重态。通过比较完整和映射系统的能量和自旋，以及在存在磁通量的情况下，通过比较电荷振荡动力学的繁殖来确认映射的有效性。新引入的RASHBA耦合显着丰富了系统动力学，影响电荷振荡的大小，并允许由于自旋旋转而引起的单线和三重态在三重态之间的受控过渡，这是由自旋轨道耦合引起的。结果表明，还讨论了使用研究系统进行量子信息处理的可能性，同时还讨论了系统在通用量子计算机中充当量子的可能扩展，并还讨论了所有五个Divincenzo标准。
The spin-sensitive charge oscillation, controlled by an external magnetic field, was recently proposed as a mechanism of transformations of qubits, defined as two-electron spin-charge Wannier molecules in a square quantum dot. The paper expands this idea by including the effects of Rashba type spin-orbit coupling. The problem is studied theoretically by mapping the system to an analytic effective Hamiltonian for 8 low energy states, comprising singlet and triplet on each dot diagonal. The validity of the mapping is confirmed by comparing the energy and spin of full and mapped system, and also by the reproduction of charge-oscillation dynamics in the presence of magnetic flux. The newly introduced Rashba coupling significantly enriches the system dynamics, affecting the magnitude of charge oscillations and allowing the controlled transitions between singlet and triplet states due to the spin rotations, induced by spin-orbit coupling. The results indicate the possibility for use of the studied system for quantum information processing, while possible extensions of the system to serve as a qubit in a universal quantum computer, fulfilling all five DiVincenzo criteria, are also discussed.
