1202.0497 (Tobias Holder et al.)

Incommensurate nematic fluctuations in two dimensional metals    [PDF]

Tobias Holder, Walter Metzner

To assess the strength of nematic fluctuations with a finite wave vector in a
two-dimensional metal, we compute the static d-wave polarization function for
tight-binding electrons on a square lattice. At Van Hove filling and zero
temperature the function diverges logarithmically at q=0. Away from Van Hove
filling the ground state polarization function exhibits finite peaks at finite
wave vectors. A nematic instability driven by a sufficiently strong attraction
in the d-wave charge channel thus leads naturally to a spatially modulated
nematic state, with a modulation vector that increases in length with the
distance from Van Hove filling. Above Van Hove filling, for a Fermi surface
crossing the magnetic Brillouin zone boundary, the modulation vector connects
antiferromagnetic hot spots.

View original: http://arxiv.org/abs/1202.0497