Conditions for Nondistortion Interrogation of Quantum System

High efficiency Nondistortion Quantum Interrogation of atoms in quantum superpositions

We consider the nondistortion quantum interrogation (NQI) of an atom prepared in a quantum superposition. By manipulating the polarization of the probe photon and making connections to interaction free measurements of opaque objects, we show that nondistortion interrogation of an atom in a quantum superposition can be done with efficiency approaching unity. However, if any component of the atom's superposition is completely transparent to the probe wave function, a nondistortion interrogation of the atom is impossible.

A general framework of nondistortion quantum interrogation

We present a general framework to study nondistortion quantum interrogation which preserves the internal state of the quantum object being detected. We obtain the necessary and sufficient condition for successful performing nondistortion interrogation for unknown quantum object when the interaction between the probe system and the detected system takes place only once. When the probe system and interrogation process have been limited we develop a mathematical frame to determine whether it is possible to realize NQI processes only relying on the choice of the original probe state. We also consi…

Nondistortion Quantum Interrogation using EPR entangled Photons

We propose a novel scheme for nondistortion quantum interrogation (NQI), defined as an interaction-free measurement which preserves the internal state of the object being detected. In our scheme, two EPR entangled photons are used as the probe and polarization sensitive measurements are performed at the four ports of the Mach-Zehnder interferometer. In comparison with the previous single photon scheme, it is shown that the two photon approach has a higher probability of initial state preserving interrogation of an atom prepared in a quantum superposition. In the case that the presence of the a…

量子传感中的时间分辨率极限

The temporal resolution limit in quantum sensing

本研究结合量子态可区分条件与量子速度极限，确立了询问时间下界，证明低于该界限时信息将不可避免丢失，并将结论推广至含时信号哈密顿量，阐明了其对磁场测量和时间分辨率的影响。

具有内在量子时间不确定性的量子重力仪

Quantum gravimetry with intrinsic quantum time uncertainty

研究了具有内在时间不确定性的时间探测对量子重力仪的影响，通过两参数量子 Fisher 信息矩阵分析，揭示了重力-时间交叉项的线性特性，并在三个基准模型中验证了重力信息的优化方法。

固态光学钟中的集体腔量子电动力学

Collective cavity quantum electrodynamics in solid-state optical clocks

针对固态频率标准受退相干限制的问题，提出三种腔QED增强询问方案，利用钍核集体耦合实现快速探测，并揭示集体协同性对频率不稳定性的关键作用及最优运行条件。