论文标题
量子多体旋转环与辅助旋转耦合：朝阳量子模型
Quantum many-body spin rings coupled to ancillary spins: The sunburst quantum Ising model
论文作者
论文摘要
我们研究了量子“朝阳模型”的地面特性，该特性由横向场中的量子式旋转组成，对称地耦合到一组辅助分离量子器，以维持残留的平移不变性以及$ \ mathbb {Z}} _2 _2 _2 $ symmetry。大尺寸的极限以两种不同的方式进行：通过保持固定任何两个相邻的辅助量子位之间的距离，或者在增加环大小的同时固定其数字。根据各种哈密顿参数的不同：对于小能量尺度$δ$，辅助子系统和小环的相互作用$κ$，我们观察到质量量的快速和非分析变化，通过一阶和持续的量子逐渐缩小良好的重新调查，我们会观察到快速且非分析的变化。相反，在保持$δ> 0 $固定并在伊辛无序阶段时，会观察到更顺畅的行为。数字$ n $的辅助旋转的效果与$ n $的足够大值相称地比例比$ \ sqrt {n} $比例。
We study the ground-state properties of a quantum "sunburst model", composed of a quantum Ising spin-ring in a transverse field, symmetrically coupled to a set of ancillary isolated qubits, to maintain a residual translation invariance and also a $\mathbb{Z}_2$ symmetry. The large-size limit is taken in two different ways: either by keeping the distance between any two neighboring ancillary qubits fixed, or by fixing their number while increasing the ring size. Substantially different regimes emerge, depending on the various Hamiltonian parameters: for small energy scale $δ$ of the ancillary subsystem and small ring-qubits interaction $κ$, we observe rapid and nonanalytic changes in proximity of the quantum transitions of the Ising ring, both first-order and continuous, which can be carefully controlled by exploiting renormalization-group and finite-size scaling frameworks. Smoother behaviors are instead observed when keeping $δ>0$ fixed and in the Ising disordered phase. The effect of an increasing number $n$ of ancillary spins turns out to scale proportionally to $\sqrt{n}$ for sufficiently large values of $n$.
