Integrability and coherence of hopping between 1D correlated electrons systems

Abstract

We present numerical evidence that the hopping of electrons between chains described by the $t-J$ model is coherent in the integrable cases ($J=0$ and $J=2$) and essentially incoherent otherwise. This effect is {\it not} related to the value of the exponent $\alpha$, (which is restricted to the interval [0,1/8] when $0\le J\le 2$), and we propose that enhanced coherence is characteristic of integrable systems.