Spontaneous breaking of four-fold rotational symmetry in two-dimensional electron systems as a topological phase transition
Abstract
Motivated by recent observations of C4 symmetry breaking in strongly correlated two-dimensional electron systems on a square lattice, we analyze this phenomenon within an extended Fermi liquid approach. It is found that the symmetry violation is triggered by a continuous topological phase transition associated with exchange of antiferromagnetic fluctuations. In contrast to predictions of mean-field theory, the structure of a part of the single-particle spectrum violating C4 symmetry is found to be highly anisotropic, with a peak located in the vicinity of saddle points.
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