Spontaneous breaking of four-fold rotational symmetry in two-dimensional electronic systems explained as a continuous topological transition
M. V. Zverev+, J. W. Clark*, Z. Nussinov*, V. A. Khodel+*1)
+Russian Research Centre Kurchatov Institute, 123182 Moscow, Russia
*McDonnell Center for the Space Science and Department of Physics,
Washington University, St.Louis, USA
Abstract
The Fermi liquid approach is applied to the problem of spontaneous
violation of the C4 symmetry in strongly correlated two-dimensional
electronic systems on a square lattice. The symmetry breaking is traced to
the existence of a topological phase transition. This continuous transition
is triggered when the Fermi line, driven by the quasiparticle interactions,
reaches the van Hove saddle points, where the group velocity vanishes and the
density of states becomes singular. An unconventional Fermi liquid emerges
beyond the implicated quantum critical point.