LOW-FIELD MAGNETOTRANSPORT STUDY OF LOCALIZATION IN A MESOSCOPIC ANTIDOT ARRAY
Low-field negative magnetoresistance has been studied on Ga+ ion focused-ion-beam-patterned GaAs/Ga1-xAlxAs heterojunctions as a function of carrier density and temperature. The negative magnetoresistance (NMR) is very large at low densities and decreases with increasing carrier density, giving a ma...
| Main Authors: | , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
1993
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| Summary: | Low-field negative magnetoresistance has been studied on Ga+ ion focused-ion-beam-patterned GaAs/Ga1-xAlxAs heterojunctions as a function of carrier density and temperature. The negative magnetoresistance (NMR) is very large at low densities and decreases with increasing carrier density, giving a magnetoconductance linear in T at low densities but closer to a lnT dependence at higher values. The NMR of this grid structure is well explained using weak localization modified by boundary scattering in an array of one-dimensional point contacts. The NMR disappears after illumination as the patterning is screened by the increased electron density. From this model, we fit the phase-breaking rate as 1/τφ=A+BT, where the constant term is attributed to boundary scattering and the linear temperature dependence arises from electron-electron scattering. © 1993 The American Physical Society. |
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