M. Cristina Diamantini, Carlo A. Trugenberger
Electron fractionalization into spinons and chargeons plays a crucial role in
2D models of strongly correlated electrons. In this paper we show that
spin-charge separation is not a phenomenon confined to lower dimensions but,
rather, we present a field-theoretic model in which it is realized in 3D. The
model involves two gauge fields, a standard one and a two-form gauge field. The
physical picture is that of a two-fluid model of chargeons and spinons
interacting by the topological BF term. When a Higgs mechanism of the second
kind for the two-form gauge field takes place, chargeons and spinons are bound
together into a charge 1 particle with spin 1/2. The mechanism is the same one
that gives spin to quarks bound into mesons in non-critical string theories and
involves the self-intersection number of surfaces in 4D space-time. A state
with free chargeons and spinons is a topological insulator. When chargeons
condense, the system becomes a topological superconductor; a condensate of
spinons, instead realizes U(1) charge confinement.
View original:
http://arxiv.org/abs/1112.3281
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