Detection of quantum critical points by a probe qubit
Detection of quantum critical points by a probe qubit
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DOI：
10.1103/physrevlett.100.100501
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发表时间：
2008-03-14
影响因子：
8.6
通讯作者：
Suter, Dieter
中科院分区：
文献类型：
--
作者：
Zhang, Jingfu;Peng, Xinhua;Suter, Dieter
当外部控制参数达到临界值时，量子系统的基态发生质的变化，从而发生量子相变。在这里，我们展示了一种通过将系统耦合到探测量子比特来研究经历相变的量子系统的技术。它直接利用量子系统在接近临界点时对微扰的敏感性增加。使用NMR量子模拟器，我们证明了这种测量技术的两种不同类型的伊辛自旋链的量子相变。
Quantum phase transitions occur when the ground state of a quantum system undergoes a qualitative change when an external control parameter reaches a critical value. Here, we demonstrate a technique for studying quantum systems undergoing a phase transition by coupling the system to a probe qubit. It uses directly the increased sensibility of the quantum system to perturbations when it is close to a critical point. Using an NMR quantum simulator, we demonstrate this measurement technique for two different types of quantum phase transitions in an Ising spin chain.