Nonperturvative behavior of the quantum phase transition to a nematic fluid

M LAWLER, D BARCI, V FERNANDEZ, E FRADKIN AND L OXMAN

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society

Año: 2006 vol. 73 p. 85101 - 85101

0163-1829

La referencia correcta es: Phys. Rev. B 73, 085101 (la primera pagina es 085101-1 y la ultima 085101-19), el sistema no permite ingresar caracteres alfanuméricos. We discuss shape (Pomeranchuk) instabilities of  the Fermisurface of a two-dimensional Fermi system using bosonization.We consider in detail the quantum critical behavior of the transitionof a two dimensional Fermi fluid to a nematic state which breaksspontaneously the rotational invariance of the Fermi liquid.We show that higher dimensional bosonization reproduces thequantum critical behavior expected from the Hertz-Millis analysis,and verify that this theory has dynamic critical exponent $z=3$.Going beyond this framework, we study the behavior of the fermiondegrees of freedom directly, and show that at quantum criticalityas well as in the the quantum nematic phase(except along a set of measure zero of symmetry-dictated directions)the quasi-particles of the normal Fermi liquid are generally wiped out.Instead, they exhibit short ranged spatial correlations that decayfaster than any power-law, with the law$|x|^{-1} exp(- extrm{const.};|x|^{1/3})$. In contrast, the fermionauto-correlation function has the behavior $|t|^{-1}  exp(-{ m const}.;|t|^{-2/3})$.In this regime we also find that, at low frequency, the  single-particle fermion density-of-states behaves as $N^*(omega)=N^*(0)+ B; omega^{2/3} logomega +ldots$, where $N^*(0)$ is larger than the Fermi liquid value, $N(0)$, and $B$ is a constant.  These results confirm thenon-Fermi liquid nature of both the quantum critical theory and of the nematicphase.