Hu, Jingshi and Parish, Meera M. and Rosenbaum, T. F. (2007) Nonsaturating magnetoresistance of inhomogeneous conductors: Comparison of experiment and simulation. Physical Review B, 75 (21). Art. No. 214203. ISSN 1098-0121. doi:10.1103/PhysRevB.75.214203. https://resolver.caltech.edu/CaltechAUTHORS:20140707-163027145
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Abstract
The silver chalcogenides provide a striking example of the benefits of imperfection. Nanothreads of excess silver cause distortions in the current flow that yield a linear and nonsaturating transverse magnetoresistance (MR). Associated with the large and positive MR is a negative longitudinal MR. The longitudinal MR only occurs in the three-dimensional limit and thereby permits the determination of a characteristic length scale set by the spatial inhomogeneity. We find that this fundamental inhomogeneity length can be as large as 10μm. Systematic measurements of the diagonal and off-diagonal components of the resistivity tensor in various sample geometries show clear evidence of the distorted current paths posited in theoretical simulations. We use a random-resistor network model to fit the linear MR, and expand it from two to three dimensions to depict current distortions in the third (thickness) dimension. When compared directly to experiments on Ag_(2±δ)Se and Ag_(2±δ)Te, in magnetic fields up to 55T, the model identifies conductivity fluctuations due to macroscopic inhomogeneities as the underlying physical mechanism. It also accounts reasonably quantitatively for the various components of the resistivity tensor observed in the experiments.
Item Type: | Article | |||||||||
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Additional Information: | © 2007 The American Physical Society. Received 3 April 2007; published 6 June 2007. We are grateful to P. B. Littlewood and M.-L. Saboungi for illuminating discussions, and to J. B. Betts for help with the high-field measurements at NHMFL. The work at the University of Chicago was supported by the US Department of Energy Grant No. DE-FG02-99ER45789. J.H. acknowledges support from the Consortium for Nanoscience Research. | |||||||||
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Issue or Number: | 21 | |||||||||
Classification Code: | PACS numbers: 72.20.My, 72.15.Gd, 72.80.Jc | |||||||||
DOI: | 10.1103/PhysRevB.75.214203 | |||||||||
Record Number: | CaltechAUTHORS:20140707-163027145 | |||||||||
Persistent URL: | https://resolver.caltech.edu/CaltechAUTHORS:20140707-163027145 | |||||||||
Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||
ID Code: | 46942 | |||||||||
Collection: | CaltechAUTHORS | |||||||||
Deposited By: | George Porter | |||||||||
Deposited On: | 09 Jul 2014 22:02 | |||||||||
Last Modified: | 10 Nov 2021 17:31 |
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