Fractional charge excitations in fermionic ladders
arXiv:cond-mat/0407593 · doi:10.1103/PhysRevB.71.161101
Abstract
The system of interacting spinless fermions hopping on a two-leg ladder in the presence of an external magnetic field is shown to possess a long range order: the bond density wave or the staggered flux phase. In both cases the elementary excitations are $Z_2$ kinks and carry one half the charge of an electron.
4 pages, 3 figures