String Theory, Quantum Phase Transitions, and the Emergent Fermi Liquid
Mihailo 
ubrovi
,
Jan Zaanen,
Koenraad Schalm*
A central problem in quantum condensed matter physics is the
critical theory governing the zero-temperature quantum phase
transition between strongly renormalized Fermi liquids as found
in heavy fermion intermetallics and possibly in high–critical
temperature superconductors. We found that the mathematics of
string theory is capable of describing such fermionic quantum
critical states. Using the anti–de Sitter/conformal field
theory correspondence to relate fermionic quantum critical fields
to a gravitational problem, we computed the spectral functions
of fermions in the field theory. By increasing the fermion density
away from the relativistic quantum critical point, a state emerges
with all the features of the Fermi liquid.
* To whom correspondence should be addressed. E-mail: kschalm{at}lorentz.leidenuniv.nl
