Submitted on April 14, 2009
Accepted on June 16, 2009
String Theory, Quantum Phase Transitions, and the Emergent Fermi Liquid
Mihailo 
ubrovi
1, Jan Zaanen 1, Koenraad Schalm 1*
1 Institute-Lorentz for Theoretical Physics, Leiden University, P.O. Box 9506, Leiden, Netherlands.
* To whom correspondence should be addressed.
Koenraad Schalm , E-mail: kschalm{at}lorentz.leidenuniv.nl
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 high Tc superconductors. Here, we present results showing that the mathematics of string theory is capable of describing such fermionic quantum critical states. Using the Anti-de-Sitter/Conformal Field Theory (AdS/CFT) correspondence to relate fermionic quantum critical fields to a gravitational problem, we compute 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.
