TY - JOUR
T1 - Quantum interference in two independently tunable parallel quantum point contacts
AU - Simmons, J. A.
AU - Hwang, S. W.
AU - Tsui, D. C.
AU - Shayegan, M.
N1 - Funding Information:
Acknowledgement - We thank L. W. Engel and I. J. Heremans for assistance. This work is supported by ONR through Contract No. N00014-89-J-1567, and NSF through Grants No. DMR-8719694 and No. DMR-892973. One of the authors (S. W. H.) thanks the Korean Government Ministry of Education for its partial financial support.
PY - 1992
Y1 - 1992
N2 - We have fabricated two independently tunable quantum point contacts in a parallel configuration, by wet etching a 2,000 Å diameter hole in the center of the constriction of a split-gate quantum point contact in an AlGaAs/GaAs heterojunction. The number of occupied subbands in each of the two channels on either side of the etched hole can be tuned independently by biasing the gates, with each channel exhibiting quantized conductance steps at integer multiples of 2e2/h, independent of the other. For B in the quantum Hall regime, periodic resistance oscillations are observed when both gate biases are fixed and B is swept. Further, periodic resistance oscillations are also observed when B and the bias on one gate is fixed, while the bias on the second gate is swept. In both cases the fluctuations are due to tunneling between opposite edge channels via magnetically bound 'edge' states encircling the etched hole, whose energies are quantized such that each encloses an integral number of flux quanta.
AB - We have fabricated two independently tunable quantum point contacts in a parallel configuration, by wet etching a 2,000 Å diameter hole in the center of the constriction of a split-gate quantum point contact in an AlGaAs/GaAs heterojunction. The number of occupied subbands in each of the two channels on either side of the etched hole can be tuned independently by biasing the gates, with each channel exhibiting quantized conductance steps at integer multiples of 2e2/h, independent of the other. For B in the quantum Hall regime, periodic resistance oscillations are observed when both gate biases are fixed and B is swept. Further, periodic resistance oscillations are also observed when B and the bias on one gate is fixed, while the bias on the second gate is swept. In both cases the fluctuations are due to tunneling between opposite edge channels via magnetically bound 'edge' states encircling the etched hole, whose energies are quantized such that each encloses an integral number of flux quanta.
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U2 - 10.1016/0749-6036(92)90257-6
DO - 10.1016/0749-6036(92)90257-6
M3 - Article
AN - SCOPUS:0026745871
SN - 0749-6036
VL - 11
SP - 223
EP - 227
JO - Superlattices and Microstructures
JF - Superlattices and Microstructures
IS - 2
ER -