发表机构
FZU - Institute of Physics of the Czech Academy of Sciences; Department of Physics, King’s College London; School of Physics, Trinity College Dublin（捷克科学院物理研究所; 伦敦国王学院物理系; 都柏林三一学院物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过量子比特探针研究温度对区分强关联系统量子相的影响，发现即使在有限温度下探针动力学仍能携带链的信息，表明量子比特探针是灵敏且鲁棒的量子相探测器。
AI 中文摘要
我们研究了温度对量子比特探针区分强关联系统中不同相的能力的影响。为此，我们研究了一个自旋-1/2海森堡XXZ链，通过纯退相位相互作用与量子比特探针耦合。在零温度下，如先前所报道的，退相干动力学在链的有隙相和无隙相中表现出不同的行为，有隙相中具有特征的强振荡，无隙相中则呈单调衰减。随着温度升高，这些振荡在有隙相中的衰减比预期慢得多，并且在无限温度下其残余仍然可见。在低温下的无隙相中，利用Luttinger液体理论，我们预测相干性随时间呈渐近指数衰减，衰减速率对各向异性参数的符号敏感。我们得出结论，即使在有限且相当低的温度下，探针动力学仍携带关于链的信息，将量子比特探针定位为相关自旋系统量子相的灵敏且鲁棒的探测器。
英文摘要
We study the effect of temperature on the ability of a qubit probe to distinguish between different phases in strongly correlated systems. Now to this end, we investigate a spin-1/2 Heisenberg XXZ chain coupled to a qubit probe via a pure dephasing interaction. At zero temperature, as reported previously, the decoherence dynamics exhibit different behavior in the gapped and gapless phases of the chain, with characteristic strong oscillations in the gapped phase and monotonic decay in the gapless phase. These oscillations decay much more slowly than expected with rising temperature in the gapped phase and their remnants are still visible at infinite temperature. In the gapless phase at low temperatures, using Luttinger liquid theory, we predict that the coherence exhibits asymptotic exponential decay in time, with the decay rate sensitive to the sign of the anisotropy parameter. We conclude that probe dynamics continue to carry information about the chain even at finite, reasonably small temperatures, positioning qubit probes as sensitive and robust detectors for quantum phases of correlated spin systems.
Comments11 pages, 5 figures
