Asymmetric response of magnetic impurity in Bernal-stacked bilayer honeycomb lattice

• 来源期刊: 中国物理B（英文版）
• 关键词: local moments bilayer honeycomb lattices quantum Monte Carlo
• 年，卷（期）: 2018,（7）
• 页码范围: 579-587
• 页数: 9页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/7/077502

摘要

We utilize the Hirsch–Fye quantum Monte Carlo method to investigate the local moment formation of a magnetic impurity in a Bernal-stacked bilayer honeycomb lattice. A tight-binding model with the two most significant inter-layer hoppings, t1 between pairs of dimer sites and t3 between pairs of non-dimer sites, is used to describe the kinetic energy of the system. The local moment formed shows an asymmetric response to the inter-layer hoppings depending on which sublattice the impurity is coupled to. In the dimer and non-dimer couplings, the effects of t1 and t3 onto the local moment are quite opposite. When tuning the local moment, this asymmetric response is observed in a wide parameter range. This asymmetric response is also discussed by the computations of spectral densities, as well as correlation functions between the magnetic impurity and the conduction electrons.