论文标题
在远程量子自旋梯子中不断变化的关键指数
Continuously varying critical exponents in long-range quantum spin ladders
论文作者
论文摘要
我们研究了具有隐藏弦顺序的rung-singlet相位的量子 - 量子行为与$ su（2）$（2）$ - 对称性的Néel相之间的量子行为，并在量子旋转梯子上具有代数衰减的未覆盖的远程海森贝格相互作用。将扰动连续统一转换（PCUT）与白色环膨胀和蒙特卡洛模拟相结合，在热力学限制下，对孤立的rung-dimer限制的热力学极限中产生了高阶串联膨胀。 rung-singlet阶段的分解允许确定临界线和整个临界指数集，这是远程相互作用的衰减指数的函数。表明，连续变化的临界指数以及远距离的平均场行为的非平凡制度使人联想到远程横向场模型。
We investigate the quantum-critical behavior between the rung-singlet phase with hidden string order and the Néel phase with broken $SU(2)$-symmetry on quantum spin ladders with algebraically decaying unfrustrated long-range Heisenberg interactions. Combining perturbative continuous unitary transformations (pCUT) with a white-graph expansion and Monte Carlo simulations yields high-order series expansions of energies and observables in the thermodynamic limit about the isolated rung-dimer limit. The breakdown of the rung-singlet phase allows to determine the critical line and the entire set of critical exponents as a function of the decay exponent of the long-range interaction. A non-trivial regime of continuously varying critical exponents as well as long-range mean-field behavior is demonstrated reminiscent of the long-range transverse-field Ising model.
