Dynamics of flux creep in underdoped single crystals of Y12xPrxBa2Cu3O72d
نویسندگان
چکیده
Transport as well as magnetic relaxation properties of the mixed state were studied on strongly underdoped Y12xPrxBa2Cu3O72d crystals. We observed two correlated phenomena—a coupling transition and a transition to quantum creep. The distribution of transport current below the coupling transition is highly nonuniform, which facilitates quantum creep. We speculate that in the mixed state below the coupling transition, where dissipation is non-Ohmic, the current distribution may be unstable with respect to self-channeling, resulting in the formation of very thin current-carrying layers.
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