1202.3109 (Jing Wang et al.)

Unconventional behavior of Dirac fermions in two-dimensional gauge
theory    [PDF]

Jing Wang, Guo-Zhu Liu

We study the unconventional behavior of massless Dirac fermions due to
interaction with a U(1) gauge field in two spatial dimensions. At zero chemical
potential, the longitudinal and transverse components of gauge interaction are
both long-ranged. There is no fermion velocity renormalization since the system
respects Lorentz invariance. At finite chemical potential, the Lorentz
invariance is explicitly broken by the finite Fermi surface. The longitudinal
gauge interaction is statically screened and becomes unimportant, whereas the
transverse gauge interaction remains long-ranged and leads to singular
renormalization of fermion velocity. The anomalous dimension of fermion
velocity is calculated by means of renormalization group method. We then
examine the influence of singular velocity renormalization on several physical
quantities, and show that they exhibit different behavior at zero and finite
chemical potential.

View original: http://arxiv.org/abs/1202.3109