Bloch oscillations in the spin-1/2 XXZ chain

Under a perfect periodic potential, the electric current density induced by a constant electric field may exhibit nontrivial oscillations, so-called Bloch oscillations, with an amplitude that remains nonzero in the large system size limit. Such oscillations have been well studied for nearly noninteracting particles and observed in experiments. In this work we revisit Bloch oscillations in strongly interacting systems. By analyzing the spin-1/2 XXZ chain, we demonstrate that the current density at special values of the anisotropy parameter Delta = - cos(pi/p) (p = 3, 4, 5, ...) in the ferromagnetic gapless regime behaves qualitatively the same as in the noninteracting case (Delta = 0) even in the weak electric field limit. When Delta deviates from these values, the amplitude of the oscillation under a weak electric field is suppressed by a factor of the system size. We estimate the strength of the electric field required to observe such a behavior using the Landau-Zener formula.

Automated summary

In this work, Bloch oscillations in strongly interacting systems are revisited. By analyzing the spin-1/2 XXZ chain, it is shown that under certain anisotropy parameter values, the behavior of current density under a weak electric field limit is qualitatively similar to the noninteracting case, with the amplitude of oscillation suppressed by the system size factor when the parameter deviates from these values. The strength of the electric field required to observe such a behavior is estimated using the Landau-Zener formula.