# The antiferromagnetic transition of UPd2Al3 break-junctions: A new realization of N-shaped current-voltage characteristics Source: [The antiferromagnetic transition of UPd2Al3 break-junctions: A new realization of N-shaped current-voltage characteristics]() Collection index: [llms.txt]() Data updated: 2025-10-24T11:26:10.053Z Authors: Yu. G. Naidyuk, K. Gloos, I. K. Yanson, N. K. Sato Published: 2004-05-06T15:15:45.000Z ## Abstract We have investigated metallic break junctions of the heavy-fermion compound UPd2Al3 at low temperatures between 0.1K and 9K and in magnetic fields up to 8T. Both the current-voltage I(V) characteristics and the dV/dI (V) spectra clearly showed the superconducting ($T\_{\\rm c}\\simeq$ 1.8K) as well as the antiferromagnetic ($T\_{\\rm N}\\simeq$14K) transition at low temperatures when the bias voltage is raised. The junctions with lateral size of order 200nm had huge critical current densities around $5\\times 10^{10} A/m^2 at the antiferromagnetic transition and hysteretic I(V) characteristics. Degrading the quality of the contacts by in situ increasing the local residual resistivity reduced the hysteresis. We show that those hysteretic I(V) curves can be reproduced theoretically by assuming the constriction to be in the thermal regime. It turns out that these point contacts represent non-linear devices with N-shaped I(V) characteristics that have a negative differential resistance like an Esaki tunnel diode. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()