Spontaneous mass generation due to phonons in a two-dimensional Dirac fermion system

A two-dimensional Dirac fermion microscope

The electron microscope has been a powerful, highly versatile workhorse in the fields of material and surface science, micro and nanotechnology, biology and geology, for nearly 80 years. The advent of two-dimensional materials opens new possibilities for realizing an analogy to electron microscopy in the solid state. Here we provide a perspective view on how a two-dimensional (2D) Dirac fermion...

Two-dimensional model of dynamical fermion mass generation in strongly coupled gauge theories.

We generalize the NF = 2 Schwinger model on the lattice by adding a charged scalar field. In this so-called χUφ2 model the scalar field shields the fermion charge, and a neutral fermion, acquiring mass dynamically, is present in the spectrum. We study numerically the mass of this fermion at various large fixed values of the gauge coupling by varying the effective four-fermion coupling, and find...

Two-Dimensional 3He: A Crucial System for Understanding Fermion Dynamics

Scale of fermion mass generation

Unitarity of longitudinal weak vector boson scattering implies an upper bound on the scale of electroweak symmetry breaking, Λ EW SB ≡ √ 8πv ≈ 1 TeV. Appelquist and Chanowitz have derived an analogous upper bound on the scale of fermion mass generation , proportional to v 2 /m f , by considering the scattering of same-helicity fermions into pairs of longitudinal weak vector bosons in a theory w...

Phonons in two-dimensional soft colloidal crystals.

The vibrational modes of pristine and polycrystalline monolayer colloidal crystals composed of thermosensitive microgel particles are measured using video microscopy and covariance matrix analysis. At low frequencies, the Debye relation for two-dimensional harmonic crystals is observed in both crystal types; at higher frequencies, evidence for van Hove singularities in the phonon density of sta...