Electrostatically defined heterojunction rings and the Aharonov-Bohm effect

C. J.B. Ford, T. J. Thornton, R. Newbury, M. Pepper, H. Ahmed, D. C. Peacock, D. A. Ritchie, J. E.F. Frost, G. A.C. Jones

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Abstract

Micron-sized loops of high-mobility two-dimensional electron gas have been made on GaAs-AlGaAs heterostructures using a novel split-gate technique. Aharonov-Bohm oscillations of amplitude up to 20% of the device resistance have been observed at very low temperatures (T<100 mK), together with h/2e oscillations which appear to be due to interference between pairs of time-reversed paths near B=0. The h/e period is found to vary by ∼25% with magnetic field, possibly as a result of the formation of edge states. In the quantum Hall effect, plateaus in Rxx are seen at high B due to variations in carrier concentration across the ring, which may cause backscattering of some edge states.

Original languageEnglish (US)
Pages (from-to)21-23
Number of pages3
JournalApplied Physics Letters
Volume54
Issue number1
DOIs
StatePublished - Dec 1 1989

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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Ford, C. J. B., Thornton, T. J., Newbury, R., Pepper, M., Ahmed, H., Peacock, D. C., Ritchie, D. A., Frost, J. E. F., & Jones, G. A. C. (1989). Electrostatically defined heterojunction rings and the Aharonov-Bohm effect. Applied Physics Letters, 54(1), 21-23. https://doi.org/10.1063/1.100818