We extend the Hertz-Millis theory of quantum phase transitions in itinerant electron systems to phases with broken discrete symmetry. By using a set of coupled flow equations derived within the functional renormalization group framework, we compute the second order phase transition line Tc (δ), where δ is a nonthermal control parameter, near a quantum critical point. We analyze the interplay and relative importance of quantum and classical fluctuations at different energy scales, and we compare the Ginzburg temperature TG to the transition temperature Tc, the latter being associated with a non-Gaussian fixed point.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 22 May 2008|