Speaker
Alexander Krikun
(Leiden University)
Description
When one considers the interplay between spontaneous and
explicit symmetry breaking in finite charge density systems,
one can observe the metal-insulator phase transition when
the spontaneous superstructure is formed on top of the
explicitly broken state. This goes under the name of
"pinning of charge density wave" and eventually can lead to
the formation of a Mott insulator, when the pinning gets
strong. I will discuss the examples of this phenomenon in
holographic models with periodic inhomogeneous and helical
homogeneous lattices. The insulating state formed in these
holographic models turns out to be quite interesting:
firstly it is gapless and inherits the scaling features of
the near horizon geometry, secondly, it demonstrates strong
suppression of conductivity even for weak explicit
translational symmetry breaking, which goes beyond the usual
picture of the conductivity being governed by the momentum
relaxation rate.
