Hidden degree of freedom and critical phase in a two-dimensional electron gas in the presence of a random magnetic field
Abstract
We establish the existence of a hidden degree of freedom associated with the critical phase of a spinless electron system in a spatially correlated random magnetic field with vanishing mean. Although implied in an earlier scenario [S.C. Zhang and D.P. Arovas, Phys. Rev. Lett. 72, 1886 (1994)], the hidden degree of freedom has not been identified or explored in existing numerical and analytical studies, however. Whereas the critical electron states are carried by the zero-field contours of the field landscape, the hidden degree of freedom in our present work is recognized as being connected to the formation of vortices in these special contours. We argue that, as opposed to the coherent backscattering mechanism of weak localization, a new type of scattering processes in the contours controls the underlying physics of localization in the random magnetic field system. In addition, we investigate the role of vortices in governing the metal-insulator transition and propose a renormalization-group diagram for the system under study.
- Publication:
-
Physical Review B
- Pub Date:
- October 2002
- DOI:
- 10.1103/PhysRevB.66.144201
- arXiv:
- arXiv:cond-mat/0202130
- Bibcode:
- 2002PhRvB..66n4201N
- Keywords:
-
- 71.30.+h;
- 72.10.-d;
- 71.23.-k;
- Metal-insulator transitions and other electronic transitions;
- Theory of electronic transport;
- scattering mechanisms;
- Electronic structure of disordered solids;
- Condensed Matter - Disordered Systems and Neural Networks
- E-Print:
- 17 pages, 16 figures