论文标题
加速量子腕骨的计算
Accelerating the computation of quantum brachistochrone
论文作者
论文摘要
量子位的有效控制在量子信息处理中起关键作用。在当前的工作中，为有或没有相互作用的单个或多个量子位的最佳量子控制得出了一组替代方程。新公式可以通过消除先前配方中涉及的冗余复杂性来大大减少计算负载。一种松弛技术设计用于数值检测涉及纠缠的最佳路径。有趣的连续对称性在拉格朗日式中鉴定出来，这表明存在物理等效的路径类别，并且可以用来去除进化的雅各布元中中性方向。在一组最佳路径集中的“基态”解决方案中，系统的时间反转对称性显示出来，这对于与对称性相关的初始状态和最终状态预计将是通用的。
Efficient control of qubits plays a key role in quantum information processing. In the current work, an alternative set of differential equations are derived for an optimal quantum control of single or multiple qubits with or without interaction. The new formulation enables a great reduction of the computation load by eliminating redundant complexity involved in previous formulations. A relaxation technique is designed for numerically detecting optimal paths involving entanglement. Interesting continuous symmetries are identified in the Lagrangian, which indicates the existence of physically equivalent classes of paths and may be utilized to remove neutral directions in the Jacobian of the evolution. In the 'ground state' solution among the set of optimal paths, the time-reversal symmetry of the system shows up, which is expected to be universal for the symmetry-related initial and final state.
