局部监测可解量子电路中的精确首次探测概率
Exact first-detection probability in a locally monitored solvable quantum circuit
- Universität Tübingen（蒂宾根大学）
- The University of Nottingham（诺丁汉大学）
- ETH Zürich（苏黎世联邦理工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究解析求解Floquet-量子East模型中局部频闪测量下的首次探测概率，通过更新方程关联Loschmidt回声，揭示测量频率调控探测统计从几何到相关性的转变，并可在数字量子模拟器上实现。
AI中文摘要：
我们研究了确定性Floquet-量子East模型中局部频闪测量与幺正量子电路动力学之间的相互作用。我们推导了首次探测到一部分量子比特回到其初始状态的概率的精确解析结果。这是通过一个更新方程实现的，该方程将首次探测概率与子系统Loschmidt回声联系起来，后者编码了被监测量子比特的有效开放动力学。由此产生的统计表现出两种机制，由测量探测时间与幺正电路动力学的弛豫时间尺度之间的竞争决定：虽然不频繁的监测导致几何首次探测统计，频繁的监测则引入相关性，表现为偏离这种几何行为。这些结果提供了局部测量反作用如何在相互作用的量子多体系统中重塑探测统计的罕见精确表征。在我们的局部协议中，返回概率由被监测子区域的大小控制，因此可以通过数字量子模拟器上的局部电路中间测量来访问。
英文摘要：
We study the interplay between local stroboscopic measurements and the unitary quantum circuit dynamics of the deterministic Floquet-quantum East model. We derive exact analytical results for the probability of first detecting a subset of qubits back in their initial state. This is achieved via a renewal equation linking the first-detection probability to the subsystem Loschmidt echo, which encodes the effective open dynamics of the monitored qubits. The resulting statistics exhibit two regimes set by the competition between the measurement probing time and the relaxation timescale of the unitary circuit dynamics: while infrequent monitoring leads to geometric first-detection statistics, frequent monitoring induces correlations that manifest as deviations from this geometric behavior. These results provide a rare exact characterization of how local measurement backaction reshapes detection statistics in an interacting quantum many-body system. In our local protocol, return probabilities are controlled by the size of the monitored subregion and can therefore be accessed on digital quantum simulators via local mid-circuit measurements.
