Strong nonlinear effects in conductivity of thin metal samples (Review Article)
I.F. Voloshin1, N.M. Makarov2, L.M. Fisher1, and V.A. Yampol'skii3
1All-Russian Electrical Engineering Institute, 12 Krasnokazarmennaya Str., Moscow 111250, Russia
2 Universidad Autónoma de Puebla, Instituo de Ciencias, Departamento de Físico-Química de Materiales Priv. 17 Norte No 3417, Col. San Miguel Hueyotlipan, Puebla, Pue., C.P. 72050, México
3A. Usikov Institute of Radiophysics and Electronics of the National Academy of Sciences of Ukraine 12 Acad. Proskura Str., Kharkiv 61085, Ukraine pos Анотація:
Received March 11, 2011
A series of papers on nontrivial nonlinear stationary and non-stationary phenomena accompanying transport current flow in thin pure single crystals of metals at low temperatures are considered. The mechanism of nonlinearity is magnetodynamical. It is related to the effect of intrinsic magnetic field of the current on electron trajectories and, thus, on metal conductivity. The magnetodynamical nonlinearity results in a nontrivial phenomenon of decreasing of the
sample resistance with increasing the current. At high currents, when the curvature radius of electron trajectories
in the intrinsic magnetic field of the current is less than the transverse sizes of the sample, a pinch effect arises. In this case, the resistivity begins to increase with increasing current. Considered also are the experimental studies into nonlinear current-voltage
characteristics of cadmium and tungsten thin samples. These experiments not only provide support for the previous theoretical predictions but they also display new nonlinear phenomena accompanying the flow of
high currents. In particular, self-oscillations of voltage were observed in the regime of preset current. When the current is increased, the spectrum of selfoscillations evolves by a definite scenario with the transition from discrete to continuous one, suggesting
that there occurs a chaotic regime.
PACS: 72.15.Gd Galvanomagnetic and other magnetotransport effects; PACS: 72.20.Ht High-field and nonlinear effects; PACS: 72.70.+m Noise processes and phenomena.
Key words: magnetodynamical nonlinearity, transport current, Pinch effect, autooscillations, stochastics.