论文标题
旋转链中的一阶过渡与量子浴
First-order transitions in spin chains coupled to quantum baths
论文作者
论文摘要
我们表明，定制耗散环境可以改变连续量子相变的特征，甚至可以在铁磁旋转链中引起一阶转变。特别地，使用数值精确的量子蒙特卡洛方法在横向磁场中的一半旋转范式链链中，我们发现在欧姆机构中，旋转耦合到局部量子玻色子浴中，甚至可以使从第二阶到第一阶的过渡，即使散发较低。此外，使用变异的平均场方法来治疗自旋旋转和自旋 - 玻色子相互作用，我们指出，相位不连续性可归因于耗散诱导的有效磁场，这与浴室量子量波动本质上相关，并且在经典浴中消失。有效场能够沿着自旋旋转相互作用的方向切换磁化的符号。结果可以在最近的量子模拟器中进行测试，并且与量子传感有关，因为自旋系统不仅可以检测非古典浴的性能，还可以检测到弱磁场的影响。
We show that tailoring the dissipative environment allows to change the features of continuous quantum phase transitions and, even, induce first order transitions in ferromagnetic spin chains. In particular, using a numerically exact quantum Monte Carlo method for the paradigmatic Ising chain of one-half spins in a transverse magnetic field, we find that spin couplings to local quantum boson baths in the Ohmic regime can drive the transition from the second to the first order even for a low dissipation strength. Moreover, using a variational mean-field approach for the treatment of spin-spin and spin-boson interactions, we point out that phase discontinuities are ascribable to a dissipation induced effective magnetic field which is intrinsically related to the bath quantum fluctuations and vanishes for classical baths. The effective field is able to switch the sign of the magnetization along the direction of spin-spin interactions. The results can be potentially tested in recent quantum simulators and are relevant for quantum sensing since the spin system could not only detect the properties of non-classical baths, but also the effects of weak magnetic fields.
