SO(3) SLAC费米子上的金属性Gross-Neveu临界性与超导电性
Metallic Gross-Neveu criticality and superconductivity on the $\mathrm{SO}(3)$ SLAC fermion
AI总结：
本研究构建SO(3)对称双层SLAC费米子模型，通过QMC模拟发现其存在两次相变，分别属于Gross-Neveu-SO(3)普适类与量子涨落驱动的一级相变，为研究狄拉克临界性和SO(3)对称超导体提供新平台。
AI中文摘要：
突破常规Gross-Neveu-Yukawa（GNY）范式的狄拉克临界性实现，已成为凝聚态物理的重要前沿。本研究引入具有可调层间相互作用的SO(3)对称双层SLAC费米子模型，该模型呈现丰富的量子相图。随着相互作用强度增加，系统经历两次不同的相变：首次相变是分隔狄拉克半金属（DSM）与SO(3)破缺有序相的连续边界，该相变规避了标准GNY普适类，因为涌现的序仅能使部分巡游费米子能隙打开；通过大规模量子蒙特卡罗（QMC）模拟，确定该相变属于具有N=6个不可约狄拉克锥的Gross-Neveu-SO(3)普适类，并精确提取对应临界指数。在更强耦合下，第二次相变驱动系统进入层间SO(3)对称超导（SC）态，研究提供了该相变是量子涨落驱动的一级相变的有力数值证据。本研究为探索标准GNY普适类之外的狄拉克临界性提供了新见解，也为实现具有SO(3)对称的超导电性提供了新平台。
英文摘要：
The realization of Dirac criticality beyond the conventional Gross-Neveu-Yukawa (GNY) paradigm has become a major frontier in condensed matter physics. In this work, we introduce an $\mathrm{SO}(3)$-symmetric bilayer SLAC fermion model with tunable inter-layer interactions that exhibits a rich quantum phase diagram. As the interaction strength increases, the system undergoes two distinct phase transitions. The primary transition is a continuous boundary separating a Dirac semimetal (DSM) from an $\mathrm{SO}(3)$-broken ordered phase. Crucially, this transition evades the standard GNY universality class because the emergent order only gaps out a subset of the itinerant fermions. Using large-scale quantum Monte Carlo (QMC) simulations, we establish that this transition belongs to the Gross-Neveu-$\mathrm{SO}(3)$ universality class with $N=6$ irreducible Dirac cones and precisely extract the corresponding critical exponents. At stronger couplings, a second transition drives the system into an inter-layer $\mathrm{SO}(3)$-symmetric superconducting (SC) state. We provide strong numerical evidence that this transition is first-order. Our study provides new insights into the exploration of Dirac criticality beyond the standard GNY universality class, and also offers a distinct platform for investigating $\mathrm{SO}(3)$-symmetric superconductivity.
