耗散诱导的Haldane链的体临界性与边界临界性
Dissipation-induced bulk and boundary criticality in the Haldane chain
AI总结：
研究与耗散欧姆浴耦合的Haldane链，通过量子蒙特卡洛模拟揭示其耗散诱导的体与边界临界性，推导广义弦序参量，为耗散调控的边界临界性研究奠定基础。
AI中文摘要：
我们研究与耗散欧姆浴耦合的Haldane链，利用大规模量子蒙特卡洛模拟，确定了向反铁磁态的二级量子相变，该反铁磁态具有自发破缺的SO(3)对称性，由动力学指数z≈2的相互作用不动点支配。我们推导了广义弦序参量，表明Haldane链的对称性保护拓扑基态在弱耗散下是稳定的，且在临界点处呈现非平凡标度维数。特别地，其拓扑边缘模式呈现非平凡边界临界性，这与从平凡态出发的等价相变不同；对于后者，我们对具有普通边界条件的耗散φ⁴理论进行了精确的ε展开。我们的设置在临界但非共形的反铁磁体中实现了自旋杂质，并为耗散控制的连续可调边界临界性铺平了道路。
英文摘要：
We study the Haldane chain coupled to a dissipative ohmic bath. Using large-scale quantum Monte Carlo simulations, we identify a second-order quantum phase transition into an antiferromagnetic state with spontaneously broken SO(3) symmetry that is governed by an interacting fixed point with dynamical exponent $z\approx 2$. We derive a generalized string order parameter which indicates that the symmetry-protected topological ground state of the Haldane chain is stable for weak dissipation and develops a nontrivial scaling dimension at criticality. In particular, its topological edge modes display nontrivial boundary criticality that is distinct from an equivalent transition out of a trivial state; for the latter, we perform an accurate $ε$ expansion of a dissipative $ϕ^4$ theory with ordinary boundary conditions. Our setup realizes a spin impurity in a critical yet nonconformal antiferromagnet and paves the way for continuously tunable boundary criticality controlled by dissipation.
