论文标题
dirac旋转液体的理论旋转$ S $三角形晶格：可能应用于$α$ -CROOH（D）
Theory of Dirac spin liquids on spin-$S$ triangular lattice: possible application to $α$-CrOOH(D)
论文作者
论文摘要
三角晶格量子抗铁磁铁最近已成为实现狄拉克旋转液体（DSL）的有前途的游乐场 - 一类高度纠缠的量子相容纳紧急量规场和无间隙的迪拉克费米。虽然以前的理论和实验主要集中在$ s = 1/2 $旋转系统上，但最近在$ s = 3/2 $ system $α$ -CROOH（D）中检测到了DSL的信号。在这项工作中，我们在三角晶格上开发了一个DSL的理论，并以旋转$ s $矩。我们认为，在最自然的情况下，旋转$ s $系统实现了$ u（2s）$ dsl，在低能时通过gapless dirac fermions描述，加上出现的$ u（2s）$ gauge field（也称为$ u（2s）$ u（2s）$ qcd $ _3 $ _3 $ _3 $）。这种情况的一个吸引人的功能是，在足够大的$ S $中，$ u（2s）$ qCD在本质上对自发对称性的破坏和限制在本质上不稳定。限制阶段只是$ 120^{\ Circ} $ Coplanar磁性订单，它在类似Heisenberg的模型上与半经典（大$ S $）的结果一致。然而，其他情况是可能的，尤其是在小$ s $时，当量子波动强劲时。对于$ s = 3/2 $，我们认为$ u（1）$ dsl在理论上也是可能的，并且在现象学上与现有测量值兼容。 One way to distinguish the $U(3)$ DSL from the $U(1)$ DSL is to break time-reversal symmetry, for example by adding a spin chirality term $\vec{S}_i\cdot(\vec{S}_j\times\vec{S}_k)$ in numerical simulations: the $U(1)$ DSL becomes the standard Kalmeyer-Laughlin手性旋转液体，具有半/反隔离激发；相比之下，$ u（3）$ dsl变成了$ su（2）_3 $拓扑订单所描述的非亚洲手性旋转液体，其fibonacci like like anyons。
Triangular lattice quantum antiferromagnet has recently emerged to be a promising playground for realizing Dirac spin liquids (DSLs) -- a class of highly entangled quantum phases hosting emergent gauge fields and gapless Dirac fermions. While previous theories and experiments focused mainly on $S=1/2$ spin systems, more recently signals of a DSL were detected in an $S=3/2$ system $α$-CrOOH(D). In this work we develop a theory of DSLs on triangular lattice with spin-$S$ moments. We argue that in the most natural scenario, a spin-$S$ system realizes a $U(2S)$ DSL, described at low energy by gapless Dirac fermions coupled with an emergent $U(2S)$ gauge field (also known as $U(2S)$ QCD$_3$). An appealing feature of this scenario is that at sufficiently large $S$, the $U(2S)$ QCD becomes intrinsically unstable toward spontaneous symmetry breaking and confinement. The confined phase is simply the $120^{\circ}$ coplanar magnetic order, which agrees with semiclassical (large-$S$) results on simple Heisenberg-like models. Other scenarios are nevertheless possible, especially at small $S$ when quantum fluctuations are strong. For $S=3/2$, we argue that a $U(1)$ DSL is also theoretically possible and phenomenologically compatible with existing measurements. One way to distinguish the $U(3)$ DSL from the $U(1)$ DSL is to break time-reversal symmetry, for example by adding a spin chirality term $\vec{S}_i\cdot(\vec{S}_j\times\vec{S}_k)$ in numerical simulations: the $U(1)$ DSL becomes the standard Kalmeyer-Laughlin chiral spin liquid with semion/anti-semion excitation; the $U(3)$ DSL, in contrast, becomes a non-abelian chiral spin liquid described by the $SU(2)_3$ topological order, with Fibonacci-like anyons.
