Interaction-induced time-symmetry breaking in driven quantum oscillators
Interaction-induced time-symmetry breaking in driven quantum oscillators
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DOI：
10.1103/physrevb.98.195444
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发表时间：
2018-11-29
影响因子：
3.7
通讯作者：
Zhang, Yaxing
中科院分区：
文献类型：
--
作者：
Dykman, M., I;Bruder, Christoph;Zhang, Yaxing
我们研究了参变驱动的量子振子，并表明，即使振子之间的弱耦合，它们也可以表现出不同的多体态与破缺的时间平移对称性。在量子相干区，对称性破缺通过非平衡量子相变发生。对于耗散振子，弱耦合的主要作用是使一个振子在其周期为2的状态之间的切换速率依赖于其他振子的状态。这允许将振荡器映射到耦合自旋的系统上。对于相同的振子，定态可以映射到具有有效温度的伊辛模型。α H表示低温。如果振子是不同的，并且远离周期2状态出现的分叉参数值，则稳态对应于在自旋系统中具有微观电流。接近分叉点的耦合不能被认为是弱的，系统映射到耦合过阻尼布朗粒子执行量子扩散的潜在景观。
We study parametrically driven quantum oscillators and show that, even for weak coupling between the oscillators, they can exhibit various many-body states with broken time-translation symmetry. In the quantumcoherent regime, the symmetry breaking occurs via a nonequilibrium quantum phase transition. For dissipative oscillators, the main effect of the weak coupling is to make the switching rate of an oscillator between its period-2 states dependent on the states of other oscillators. This allows mapping the oscillators onto a system of coupled spins. For identical oscillators, the stationary state can be mapped on that of the Ising model with an effective temperature. alpha h, for low temperature. If the oscillators are different and are away from the bifurcation parameter values where the period-2 states emerge, the stationary state corresponds to having a microscopic current in the spin system. Close to the bifurcation point the coupling cannot be considered weak and the system maps onto coupled overdamped Brownian particles performing quantum diffusion in a potential landscape.