论文标题
在有限温度下掺杂的假蛋白-1费米子系统中的rkky相互作用
RKKY interaction in a doped pseudospin-1 fermion system at finite temperature
论文作者
论文摘要
我们研究了$α-\ Mathcal {t} _3 $模型中磁杂质的rkky相互作用，该模型托有带有两个色散和一个平面频段的伪季节-1费米子。通过使用有效的低能哈密顿量，我们计算了放置在相同或不同sublattices上的杂质的rkky耦合。我们发现有三种类型的相互作用取决于模型参数定义了sublattices之间跳的相对强度，其中两个可以简化为石墨烯盒，而第三个则是新的，并且由于存在平坦的零能带。我们根据梅林 - 巴恩斯类型积分来得出RKKY相互作用的一般分析表达式，并分析了不同的限制案例。考虑了有限的化学潜力和温度以及大距离的渐近造成病例。我们表明，位于不同边缘位点的杂质之间的相互作用在小掺杂时显示出非常强的温度依赖性，是平坦带的直接结果。讨论了与$ \ Mathcal {t} _3 $ lattice应用于零掺杂的rkky相互作用的符号的微妙之处，与分散平坦频段的存在有关。
We study the RKKY interaction of magnetic impurities in the $α-\mathcal{T}_3$ model which hosts pseudospin-1 fermions with two dispersive and one flat bands. By using the effective low-energy Hamiltonian we calculate the RKKY coupling for impurities placed on the same or different sublattices. We find that there are three types of interaction, which depend on the model parameter defining the relative strength of hoppings between sublattices, two of them can be reduced to graphene case while the third one is new and is due to the presence of a flat zero-energy band. We derive general analytical expressions for the RKKY interaction in terms of Mellin-Barnes type integrals and analyze different limiting cases. The cases of finite chemical potential and temperature, as well as asymptotic at large distances are considered. We show that the interaction between impurities located at different rim sites displays a very strong temperature dependence at small doping being a direct consequence of the flat band. The subtleties of the theorem for signs of the RKKY interaction at zero doping, as applied to the $\mathcal{T}_3$ lattice, related to the existence of a dispersionless flat band are discussed.
