Nonequilibrium effective field theory for absorbing state phase transitions in driven open quantum spin systems
Nonequilibrium effective field theory for absorbing state phase transitions in driven open quantum spin systems
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DOI：
10.1103/physrevb.95.014308
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发表时间：
2017-01-27
影响因子：
3.7
通讯作者：
Diehl, Sebastian
中科院分区：
文献类型：
--
作者：
Buchhold, Michael;Everest, Benjamin;Diehl, Sebastian
从相变到吸收态是脱离平衡的临界现象的最简单的例子。这些模型的特点是存在一个波动的配置，动态不能离开，这已被证明是一个相当严格的要求，在实验中。最近，一项在冷原子气体的高度可调系统中寻求这种跃迁的提议提供了探测这种物理学的机会，同时也研究了这些跃迁对量子相干效应的鲁棒性。在这里，我们特别关注经典和量子波动之间的相互作用，在一个简单的驱动开放的量子模型，在经典的限制，再现接触过程，这是已知的进行连续过渡的“定向渗透”的普适性类。我们推导出一个有效的长波场理论，本类的开放自旋系统，并表明，由于量子涨落，过渡的性质从二阶到一阶的变化，通过一个双临界点，这似乎是属于，而不是“三临界定向渗透”类。
Phase transitions to absorbing states are among the simplest examples of critical phenomena out of equilibrium. The characteristic feature of these models is the presence of a fluctuationless configuration which the dynamics cannot leave, which has proved a rather stringent requirement in experiments. Recently, a proposal to seek such transitions in highly tunable systems of cold-atomic gases offers to probe this physics and, at the same time, to investigate the robustness of these transitions to quantum coherent effects. Here, we specifically focus on the interplay between classical and quantum fluctuations in a simple driven open quantum model which, in the classical limit, reproduces a contact process, which is known to undergo a continuous transition in the "directed percolation" universality class. We derive an effective long-wavelength field theory for the present class of open spin systems and show that, due to quantum fluctuations, the nature of the transition changes from second to first order, passing through a bicritical point which appears to belong instead to the "tricritical directed percolation" class.