The shape of the V-I characteristics leading to a peak in the differential resistance r_d=dV/dI in the vicinity of the order-disorder transition in NbSe2 is investigated. r_d is large when measured by dc current. However, for a small Iac on a dc bias r_d decreases rapidly with frequency, even at a few Hz, and displays a large out-of-phase signal. In contrast, the ac response increases with frequency in the absence of dc bias. These surprisingly opposite phenomena and the peak in r_d are shown to result from a dynamic coexistence of two vortex matter phases rather than from the commonly assumed plastic depinning.
@article{arxiv.cond-mat/0207028,
title = {V-I characteristics in the vicinity of order-disorder transition in vortex matter},
author = {Y. Paltiel and Y. Myasoedov and E. Zeldov and G. Jung and M. L. Rappaport and D. E. Feldman and M. J. Higgins and S. Bhattacharya},
journal= {arXiv preprint arXiv:cond-mat/0207028},
year = {2009}
}
Comments
12 pages 4 figures. Accepted for publication in PRB rapid