Report
Evidence of Novel Quasiparticles in a Strongly Interacting Two-Dimensional Electron System: Giant Thermopower and Metallic Behaviour
| العنوان: | Evidence of Novel Quasiparticles in a Strongly Interacting Two-Dimensional Electron System: Giant Thermopower and Metallic Behaviour |
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| المؤلفون: | Narayan, Vijay, Pepper, M., Griffths, J., Beere, H., Sfigakis, F., Jones, G., Ritchie, D., Ghosh, A. |
| المصدر: | J Low Temp Phys 171, 626 (2013) |
| سنة النشر: | 2012 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics |
| الوصف: | We report thermopower ($S$) and electrical resistivity ($\rho_{2DES}$) measurements in low-density (10$^{14}$ m$^{-2}$), mesoscopic two-dimensional electron systems (2DESs) in GaAs/AlGaAs heterostructures at sub-Kelvin temperatures. We observe at temperatures $\lesssim$ 0.7 K a linearly growing $S$ as a function of temperature indicating metal-like behaviour. Interestingly this metallicity is not Drude-like, showing several unusual characteristics: i) the magnitude of $S$ exceeds the Mott prediction valid for non-interacting metallic 2DESs at similar carrier densities by over two orders of magnitude; and ii) $\rho_{2DES}$ in this regime is two orders of magnitude greater than the quantum of resistance $h/e^2$ and shows very little temperature-dependence. We provide evidence suggesting that these observations arise due to the formation of novel quasiparticles in the 2DES that are not electron-like. Finally, $\rho_{2DES}$ and $S$ show an intriguing decoupling in their density-dependence, the latter showing striking oscillations and even sign changes that are completely absent in the resistivity. Comment: QFS2012 Conference proceedings, Journal of Low Temperature Physics, accepted (figure and discussion added upon referee suggestions) |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1007/s10909-012-0718-0 |
| URL الوصول: | http://arxiv.org/abs/1208.2285 |
| رقم الانضمام: | edsarx.1208.2285 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1007/s10909-012-0718-0 |
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