General conditions are formulated that allow us to determine which quantum phase transitions in itinerant electron systems can be described by a local Landau-Ginzburg-Wilson (LGW) theory solely in terms of the order parameter. A crucial question is the degree to which the order parameter fluctuations couple to other soft modes. Three general classes of zero-wave-number order parameters, in the particle-hole spin-singlet and spin-triplet channels and in the particle-particle channel, respectively, are considered. It is shown that the particle-hole spin-singlet class does allow for a local LGW theory, while the other two classes do not. The implications of this result for the critical behavior at various quantum phase transitions are discussed, as is the connection with nonanalyticities in the wave-number dependence of order-parameter susceptibilities in the disordered phase.
D. Belitz et al., "Local Versus Nonlocal Order-Parameter Field Theories for Quantum Phase Transitions," Physical Review B - Condensed Matter and Materials Physics, vol. 65, no. 16, pp. 1651121-1651128, American Physical Society (APS), Apr 2002.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevB.65.165112
Keywords and Phrases
acceleration; electron; elementary particle; molecular dynamics; phase transition; quantum mechanics; quantum theory; waveform
International Standard Serial Number (ISSN)
Article - Journal
© 2002 American Physical Society (APS), All rights reserved.