论文标题
使用10db-sub-Heisenberg对相空间轨迹进行全面监测
Full monitoring of phase-space trajectories with 10dB-sub-Heisenberg imprecision
论文作者
论文摘要
通常，只能通过同时测量两个不强制的观测值x和y跨越相空间来完全监测量子状态的变化。耦合到热环境的测量设备在一次提供的一对值，其具有最小的不确定性产品，由海森伯格不确定性关系设定，从而限制了监视的精度。在这里，我们报告了一种光学测量设置，该设置能够监视量子状态在相空间（<x（t）>; <y（t）>）中的时间变化，其不重点为10 \，低于海森伯格的不确定性限制。我们的设置在随后的时间T_I时同时测量提供了一对值（x（t_i）; y（t_i））。测量引用不与热环境耦合，而是通过纠缠量子状态建立的。我们在监测任意时间依赖性位移中减少量子不精确的十倍减少的实现支持了纠缠增强的计量和传感所需的量子技术以及基于测量的量子计算。
The change of a quantum state can generally only be fully monitored through simultaneous measurements of two non-commuting observables X and Y spanning a phase space. A measurement device that is coupled to the thermal environment provides at a time a pair of values that have a minimal uncertainty product set by the Heisenberg uncertainty relation, which limits the precision of the monitoring. Here we report on an optical measurement setup that is able to monitor the time dependent change of the quantum state's displacement in phase space (< X (t)>; < Y (t)>) with an imprecision 10\,dB below the Heisenberg uncertainty limit. Our setup provides pairs of values (X(t_i); Y(t_i)) from simultaneous measurements at subsequent times t_i. The measurement references are not coupled to the thermal environment but are established by an entangled quantum state. Our achievement of a tenfold reduced quantum imprecision in monitoring arbitrary time-dependent displacements supports the potential of the quantum technology required for entanglement-enhanced metrology and sensing as well as measurement-based quantum computing.
