Quantum Phase Transition in the Finite Jaynes-Cummings Lattice Systems
Quantum Phase Transition in the Finite Jaynes-Cummings Lattice Systems
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DOI：
10.1103/physrevlett.117.123602
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发表时间：
2016-09-13
影响因子：
8.6
通讯作者：
Plenio, Martin B.
中科院分区：
文献类型：
--
作者：
Hwang, Myung-Joong;Plenio, Martin B.
相变通常被认为只发生在大量系统元件的化学极限中。本文利用精确可解的Jaynes-Cummings（JC）模型及其在有限JC晶格上的推广，证明了自旋和玻色子耦合的有限分量系统可以发生量子相变。对于JC模型，我们发现了一个连续的量子点破缺，一个宏观占据的光子凝聚作为基态，和一个Goldstone模式作为低能激发。对于两个位置的JC晶格，我们分析表明，它经历了一个莫特绝缘体超流QPT。我们确定的基本原则的出现有限系统QPT的原子能量和原子和玻色子模式之间的相互作用强度增加的组合，这使得探索越来越大的一部分无限维希尔伯特空间的玻色子模式。这表明有限系统相变将存在于广泛的物理系统中。
Phase transitions are commonly held to occur only in the thermodynamical limit of a large number of system components. Here, we exemplify at the hand of the exactly solvable Jaynes-Cummings (JC) model and its generalization to finite JC lattices that finite component systems of coupled spins and bosons may exhibit quantum phase transitions (QPTs). For the JC model we find a continuous symmetry-breaking QPT, a photonic condensate with a macroscopic occupation as the ground state, and a Goldstone mode as a low-energy excitation. For the two site JC lattice we show analytically that it undergoes a Mott-insulator to superfluid QPT. We identify as the underlying principle of the emergence of finite system QPTs the combination of increasing atomic energy and increasing interaction strength between the atom and the bosonic mode, which allows for the exploration of an increasingly large portion of the infinite dimensional Hilbert space of the bosonic mode. This suggests that finite system phase transitions will be present in a broad range of physical systems.