Dephasing time and magnetoresistance of two-dimensional electron gas in spatially modulated magnetic fields
| Autor: | Melnikov, A. S., Mironov, S. V., Sharov, S. V. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.81.115308 |
| Popis: | The effect of a spatially modulated magnetic field on the weak localization phenomenon in two-dimensional electron gas (2DEG) is studied. Both the dephasing time $\tau_H$ and magnetoresistance are shown to reveal a nontrivial behavior as functions of the characteristics of magnetic field profiles. The magnetic field profiles with rather small spatial scales $d$ and modulation amplitudes $H_0$ such that $H_0d^2\ll\hbar c/e$ are characterized by the dephasing rate $\tau_H^{-1}\propto H_0^2d^2$. The increase in the flux value $H_0d^2$ results in a crossover to a standard linear dependence $\tau_H^{-1}\propto H_0$. Applying an external homogeneous magnetic field $H$ one can vary the local dephasing time in the system and affect the resulting average transport characteristics. We have investigated the dependence of the average resistance vs the field $H$ for some generic systems and predict a possibility to observe a positive magnetoresistance at not too large $H$ values. The resulting dependence of the resistance vs $H$ should reveal a peak at the field values $H\sim H_0$. Comment: 12 pages, 5 figures |
| Databáze: | arXiv |
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