Strain-tuning of edge magnetism in zigzag graphene nanoribbons

Abstract

Using the determinant quantum Monte-Carlo method, we elucidate the strain tuning of edge magnetism in zigzag graphene nanoribbons. Our intensive numerical results show that a relatively weak Coulomb interaction may induce a ferromagnetic-like behaviour with a proper strain, and the edge magnetism can be enhanced greatly as the strain along the zigzag edge increases, which provides another way to control graphene magnetism even at room temperature.

Anisotropy Engineering Edge Magnetism in Zigzag Honeycomb Nanoribbons*

“…When the absolute value of t 2 /|t 1 | is larger than 1.0 up to 4.0, the edge magnetic susceptibility almost linearly increases with the increasing t 2 /|t 1 | as is shown in the inset of Fig.2. While, for the absolute value of t 2 /|t 1 | smaller than 1 down to 0, the magnetic susceptibility slightly increase, which is similar as that in zigzag graphene nanoribbons [42]. Therefore, we may assert that stronger anisotropy can induce stronger edge magnetism in zigzag honeycomb nanoribbons.…”

“…As a well-controlled route, strain engineering is often utilized to modulate the magnetic properties of 2D materials and the corresponding nanostructures [15,[39][40][41]. For ZGNRs, applying strain along the zigzag direction have been theoretically proposed to reinforce the edge magnetism [27,28,42]. The anisotropy induced by strain leads to the displacement of the Dirac points.…”

“…Thus the electronic correlation effect is enhanced by the higher DOS in the extended flat band, which catalyses the enhancement of edge magnetism. The proper strain even could trigger the room-temperature edge magnetism under the suitable Coulomb interaction [42]. Distinct from graphene, the puckered structure of phosphorene with a honeycomb lattice endows this material with strong anisotropy [43].…”

Multi-orbital physics of edge-magnetism in a Hubbard model of transition-metal dichalcogenide nanoribbons: Comparing Mean Field Theory and Determinant Quantum Monte Carlo

“…However, the sensitivity to the filling of the edge was not considered. In zGNRs and also phosphorene nanoribbons, edge magnetism has been studied using the unbiased, numerically exact determinant Quantum Monte Carlo (DetQMC) method [55][56][57][58][59]. The results for zGNRs further support the emergence of edgemagnetic order from electron-electron interactions and it is possible to make a direct comparison between DetQMC and MFT results.…”

“…DetQMC is commonly used to simulate interacting models of 2D nanostructures [56,58,59,[68][69][70][71][72]. It is based on the Hubbard Stratonovich transformation, which allows one to map the Hubbard model onto a Hamiltonian of independent fermions coupled to a binary auxiliary field.…”