The shape of the V-I characteristics leading to a peak in the differential resistance rd=dV/dI in the vicinity of the order-disorder transition in NbSe2 is investigated. rd is large when measured by dc current. However, for a small Iac on a dc bias, rd decreases rapidly with frequency, even at a few hertz, 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 rd are shown to result from a dynamic coexistence of two vortex matter phases rather than from the commonly assumed plastic depinning.
|Original language||American English|
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1 Aug 2002|