Power-Law Conductivity inside the Mott Gap: Application to κ-(BEDT-TTF)2Cu2(CN)3
Abstract
The charge dynamics of spin-liquid states described by U(1) gauge theory coupling to fermionic spinons is discussed in this paper. We find that the gapless spinons give rise to a power-law optical conductivity inside the charge gap. The theory is applied to explain the unusual optical conductivity observed recently in the organic compound κ-(BEDT-TTF)2Cu2(CN)3. We also propose an optical experiment to search for the in-gap excitations in the kagome spin-liquid insulator.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2007
- DOI:
- 10.1103/PhysRevLett.99.156402
- arXiv:
- arXiv:0706.0050
- Bibcode:
- 2007PhRvL..99o6402N
- Keywords:
-
- 71.27.+a;
- 71.30.+h;
- Strongly correlated electron systems;
- heavy fermions;
- Metal-insulator transitions and other electronic transitions;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 10 pages, 2 figures