• 文献标题:   Mechanical graphene
  • 文献类型:   Article
  • 作  者:   SOCOLAR JES, LUBENSKY TC, KANE CL
  • 作者关键词:   metamaterial, topological mechanic, graphene, vibrational mode, edge mode, weyl mode
  • 出版物名称:   NEW JOURNAL OF PHYSICS
  • ISSN:   1367-2630
  • 通讯作者地址:   Duke Univ
  • 被引频次:   7
  • DOI:   10.1088/1367-2630/aa57bb
  • 出版年:   2017

▎ 摘  要

We present a model of a mechanical system with a vibrational mode spectrum identical to the spectrum of electronic excitations in a tight-binding model of graphene. The model consists of point masses connected by elastic couplings, called 'tri-bonds',that implement certain three-body interactions, which can be tuned by varying parameters that correspond to the relative hopping amplitudes on the different bond directions in graphene. In the mechanical model, this is accomplished by varying the location of a pivot point that determines the allowed rigid rotations of a single tri-bond. The infinite system constitutes a Maxwell lattice, with the number of degrees of freedom equal to the number of constraints imposed by the tri-bonds. We construct the equilibrium and compatibility matrices and analyze the model's phase diagram, which includes spectra with Weyl points for some placements of the pivot and topologically polarized phases for others. Wethen discuss the edge modes and associated states of self stress for strips cut from the periodic lattice. Finally, we suggest a physical realization of the tri-bond, which allows access to parameter regimes not available to experiments on (strained) graphene and may be used to create other two-dimensional mechanical metamaterials with different spectral features.