Unconventional Metallicity and Giant Thermopower in a Strongly Interacting Two Dimensional Electron System
| Autor: | Narayan, Vijay, Goswami, Srijit, Pepper, Michael, Griffiths, Jonathan, Beere, Harvey, Sfigakis, Francois, Jones, Geb, Ritchie, Dave, Ghosh, Arindam |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 86, 125406 (2012) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.86.125406 |
| Popis: | We present thermal and electrical transport measurements of low-density (10$^{14}$ m$^{-2}$), mesoscopic two-dimensional electron systems (2DESs) in GaAs/AlGaAs heterostructures at sub-Kelvin temperatures. We find that even in the supposedly strongly localised regime, where the electrical resistivity of the system is two orders of magnitude greater than the quantum of resistance $h/e^2$, the thermopower decreases linearly with temperature indicating metallicity. Remarkably, the magnitude of the thermopower exceeds the predicted value in non-interacting metallic 2DESs at similar carrier densities by over two orders of magnitude. Our results indicate a new quantum state and possibly a novel class of itinerant quasiparticles in dilute 2DESs at low temperatures where the Coulomb interaction plays a pivotal role. Comment: 8 pages, 8 figures (version to appear in Phys. Rev. B) |
| Databáze: | arXiv |
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