Avalanche breakdown in GaTa4Se8−xTex narrow-gap Mott insulators
| Autor: | Marcelo J. Rozenberg, Pablo Stoliar, Etienne Janod, Vincent Guiot, Laurent Cario, Tristan Cren, Dimitri Roditchev, Benoit Corraze, Vinh Ta Phuoc |
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| Rok vydání: | 2013 |
| Předmět: |
Condensed Matter::Quantum Gases
Physics Multidisciplinary Zener effect Condensed matter physics Dielectric strength Condensed Matter::Other business.industry Mott insulator General Physics and Astronomy 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology 01 natural sciences General Biochemistry Genetics and Molecular Biology Avalanche breakdown Mott transition Semiconductor Electric field 0103 physical sciences Condensed Matter::Strongly Correlated Electrons Zener diode 010306 general physics 0210 nano-technology business |
| Zdroj: | Nature Communications. 4 |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/ncomms2735 |
| Popis: | Mott transitions induced by strong electric fields are receiving a growing interest. Recent theoretical proposals have focused on the Zener dielectric breakdown in Mott insulators, however experimental studies are still too scarce to conclude about the mechanism. Here we report a study of the dielectric breakdown in the narrow gap Mott insulators GaTa$_4$Se$_{8-x}$Te$_x$. We find that the I-V characteristics and the magnitude of the threshold electric field (E$_{th}$) do not correspond to a Zener breakdown, but rather to an avalanche breakdown. E$_{th}$ increases as a power law of the Mott Hubbard gap (E$_g$), in surprising agreement with the universal law E$_{th}$ $\propto$E$_g$$^{2.5}$ reported for avalanche breakdown in semiconductors. However, the delay time for the avalanche that we observe in Mott insulators is over three orders of magnitude longer than in conventional semiconductors. Our results suggest that the electric field induces local insulator-to-metal Mott transitions that create conductive domains which grow to form filamentary paths across the sample. |
| Databáze: | OpenAIRE |
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