2005/11/30 by Ki-Seok Kim, Ki‐Seok Kim
Physics and Astronomy · #Charge (physics) #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Deconfinement #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum critical point #Quantum mechanics #Quantum phase transition #Randomness #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.75.075105
published as Phys. Rev. B 75, 075105 (2007) · adding a renormalization group analysis with a random fugacity term as an effect of randomness on a deconfined quantum critical point
arxiv created 2007/01/03 · openalex publication_date 2007/02/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We derive an effective field theory for the competition between superconductivity (SC) and charge density waves (CDWs) by employing the SO(3) pseudospin representation of the SC and CDW order parameters. One important feature in the effective nonlinear \ensuremathσ model is the emergence of a Berry phase even at half filling, originating from the competition between SC and CDWs, i.e., the pseudospin symmetry. A-well known conflict between the previous studies of Oshikawa [Phys. Rev. Lett. 84, 1535 (2000)] and Lee and Shankar [Phys. Rev. Lett. 65, 1490 (1990)] is resolved by the appearance of the Berry phase. The Berry phase contribution allows a deconfined quantum critical point of fractionalized charge excitations with e instead of 2e in the SC-CDW quantum transition at half filling. Furthermore, we investigate the stability of the deconfined quantum criticality against quenched randomness by performing a renormalization group analysis of an effective vortex action. We argue that, although randomness results in a weak disorder fixed point differing from the original deconfined quantum critical point, deconfinement of the fractionalized charge excitations still survives at the disorder fixed point owing to a nonzero fixed point value of the vortex charge.