Fractional Topological Insulators in Three Dimensions
Abstract
Topological insulators can be generally defined by a topological field theory with an axion angle θ of 0 or π. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal T invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization P3, and a “halved” fractional quantum Hall effect on the surface with Hall conductance of the form σH=(p)/(q)(e2)/(2h) with p, q odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged “quarks” coupled to a deconfined non-Abelian SU(3) “color” gauge field, where the fractional charge of the quarks changes the quantization condition of P3 and allows fractional values consistent with T invariance.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2010
- DOI:
- 10.1103/PhysRevLett.105.246809
- arXiv:
- arXiv:1004.3628
- Bibcode:
- 2010PhRvL.105x6809M
- Keywords:
-
- 73.43.-f;
- 11.15.-q;
- 71.27.+a;
- 75.80.+q;
- Quantum Hall effects;
- Gauge field theories;
- Strongly correlated electron systems;
- heavy fermions;
- Magnetomechanical and magnetoelectric effects magnetostriction;
- Condensed Matter - Strongly Correlated Electrons;
- High Energy Physics - Theory
- E-Print:
- 4+epsilon pages, 1 figure