Spin-charge states of correlated electrons in a one-dimensional quantum dot
attached to interacting leads are studied in the non-linear transport regime.
With non-symmetric tunnel barriers, regions of negative differential
conductance induced by spin-charge separation are found. They are due to a
correlation-induced trapping of higher-spin states without magnetic field, and
associated with a strong increase in the fluctuations of the electron spin.Comment: REVTEX, 4 pages including 3 figures; Accepted for publication on
Physical Review Letter
