Lecturer: Prof. Dror Orgad
Affiliation: Racah Institute of Physics,
The Hebrew University of Jerusalem
Abstract:
The pseudogap state of the cuprate high-
temperature superconductors harbors
various fluctuating electronic orders. In
particular, recent nuclear magnetic
resonance and x-ray scattering
measurements have found evidence of
charge-density wave (CDW) fluctuations,
here, we look to reproduce the
experimental phenomenology using a non-
linear sigma model of a layered system
where superconductivity and CDW orders
compete. Using a large-N approximation,
and Monte-Carlo simulations, we show
that weak inter-layer coupling can stabilize
long-range CDW order only in the
presence of a magnetic field, which
suppresses the superconducting order
parameter inside vortex cores. This fact is
related to the low temperature behavior of
the CDW structure factor, which vanishes
linearly with decreasing temperature in
the absence of a magnetic field and
diverges in its presence. Such behavior is
inconsistent with x-ray scattering
measurements of underdoped cuprates.
On the other hand, qualitative agreement
with experiments is obtained when the
effect of a random pinning potential is
taken into account in our simulations and
large-N analysis. Our findings, therefore,
point to the importance of disorder in
establishing the experimentally observed
signatures.