1 research outputs found
Coupled Dirac Fermions and Neutrino-like Oscillations in Twisted Bilayer Graphene
The low-energy quasiparticles in
graphene can be described by a
Dirac–Weyl Hamiltonian for massless fermions, hence graphene
has been proposed to be an effective medium to study exotic phenomena
originally predicted for relativistic particle physics, such as Klein
tunneling and Zitterbewegung. In this work, we show that another important
particle-physics phenomenon, the neutrino oscillation, can be studied
and observed in a particular graphene system, namely, twisted bilayer
graphene. It has been found that graphene layers grown epitaxially
on SiC or by the chemical vapor deposition method on metal substrates
display a stacking pattern with adjacent layers rotated by an angle
with respect to each other. The quasiparticle states in two distinct
graphene layers act as neutrinos with two flavors, and the interlayer
interaction between them induces an appreciable coupling between these
two “flavors” of massless fermions, leading to neutrino-like
oscillations. In addition, our calculation shows that anisotropic
transport properties manifest in a specific energy window, which is
accessible experimentally in twisted bilayer graphene. Combining two
graphene layers enables us to probe the rich physics involving multiple
interacting Dirac fermions