Beating of Aharonov-Bohm oscillations in a closed-loop interferometer
SCIE
SCOPUS
- Title
- Beating of Aharonov-Bohm oscillations in a closed-loop interferometer
- Authors
- Jo, S; Khym, GL; Chang, DI; Chung, Y; Lee, HJ; Kang, K; Mahalu, D; Umansky, V
- Date Issued
- 2007-07
- Publisher
- AMER PHYSICAL SOC
- Abstract
- One of the points at issue with closed-loop-type interferometers is beating in the Aharonov-Bohm (AB) oscillations. Recent observations suggest the possibility that the beating results from the Berry-phase pickup by the conducting electrons in materials with the strong spin-orbit interaction (SOI). In this study, we also observed beats in the AB oscillations in a gate-defined closed-loop interferometer fabricated on a GaAs/Al0.3Ga0.7As two-dimensional electron-gas heterostructure. Since this heterostructure has very small SOI, the picture of the Berry-phase pickup is ruled out. The observation of beats in this study, with the controllability of forming a single transverse subband mode in both arms of our gate-defined interferometer, also rules out the often-claimed multiple transverse subband effect. It is observed that nodes of the beats with an h/2e period exhibit a parabolic distribution for varying the side gate. These results are shown to be well interpreted, without resorting to the SOI effect, by the existence of two-dimensional multiple longitudinal modes in a single transverse subband. The Fourier spectrum of measured conductance, despite showing multiple h/e peaks with the magnetic-field dependence that are very similar to that from strong-SOI materials, can also be interpreted as the two-dimensional multiple-longitudinal-modes effect.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/12173
- DOI
- 10.1103/PhysRevB.76.035110
- ISSN
- 1098-0121
- Article Type
- Article
- Citation
- PHYSICAL REVIEW B, vol. 76, no. 3, page. 35110 - 35110, 2007-07
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