Buonsante P, Vezzani A
Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italy.
Phys Rev Lett. 2007 Mar 16;98(11):110601. doi: 10.1103/PhysRevLett.98.110601.
We analyze the quantum phase transition in the Bose-Hubbard model borrowing two tools from quantum-information theory, i.e., the ground-state fidelity and entanglement measures. We consider systems at unitary filling comprising up to 50 sites and show for the first time that a finite-size scaling analysis of these quantities provides excellent estimates for the quantum critical point. We conclude that fidelity is particularly suited for revealing a quantum phase transition and pinning down the critical point thereof, while the success of entanglement measures depends on the mechanisms governing the transition.
我们借鉴量子信息论中的两个工具，即基态保真度和纠缠度量，来分析玻色 - 哈伯德模型中的量子相变。我们考虑了占据多达50个格点的幺正填充系统，并首次表明对这些量进行有限尺寸标度分析能够为量子临界点提供出色的估计。我们得出结论，保真度特别适合于揭示量子相变并确定其临界点，而纠缠度量的成功则取决于控制相变的机制。
