论文标题
竞争性淋巴结D波超导性和抗铁磁性
Competing nodal d-wave superconductivity and antiferromagnetism
论文作者
论文摘要
竞争的非常规的超导性和抗势力磁性广泛存在于几种密切相关的量子材料中，这些量子材料的直接模拟通常会遭受费米符号问题。在这里，我们报告了无偏量蒙特卡洛（QMC）模拟在无标志 - 问题上的排斥玩具模型上，其现场对称性与2D平方晶格上的标准Hubbard模型相同。使用QMC补充了平均场和连续性场理论的参数，我们发现它具有三个不同的阶段：淋巴结D波相，一个抗fiferromagnet和一个中间阶段，该阶段载有共存的抗fiferromagnetism和无d-d-wave d-wave superconcoditivity。 2+1-D XY通用类别描述了从共存阶段到抗铁磁铁的过渡，而Heisenberg-Gross-Neveu理论描述了从共存阶段到鼻子D-WAVE阶段的过渡。我们相图的拓扑类似于分层有机材料的拓扑，它们的压力调节了莫特（Mott）从抗fiferromagnet到非常规超导体的过渡。
Competing unconventional superconductivity and antiferromagnetism widely exist in several strongly correlated quantum materials whose direct simulation generally suffers from fermion sign problem. Here we report unbiased Quantum Monte Carlo (QMC) simulations on a sign-problem-free repulsive toy model with same onsite symmetries as the standard Hubbard model on a 2D square lattice. Using QMC, supplemented with mean-field and continuum field-theory arguments, we find that it hosts three distinct phases: a nodal d-wave phase, an antiferromagnet, and an intervening phase which hosts coexisting antiferromagnetism and nodeless d-wave superconductivity. The transition from the coexisting phase to the antiferromagnet is described by the 2+1-D XY universality class, while the one from the coexisting phase to the nodal d-wave phase is described by the Heisenberg-Gross-Neveu theory. The topology of our phase diagram resembles that of layered organic materials which host pressure tuned Mott transition from antiferromagnet to unconventional superconductor at half-filling.
