ac response of quantum point contacts with a split-gate configuration

Please use this identifier to cite or link to this item: http://hdl.handle.net/2241/114019

Title:	ac response of quantum point contacts with a split-gate configuration
Authors:	Sasaoka, Kenji Yamamoto, Takahiro Watanabe, Satoshi Shiraishi, Kenji 白石, 賢二
Issue Date:	Sep-2011
Publisher:	American Physical Society
Journal Title:	Physical review B
Volume:	84
Issue:	12
Start Page:	125403
DOI:	10.1103/PhysRevB.84.125403
Abstract:	The alternating-current response of a quantum point contact (QPC) is numerically investigated using the nonequilibrium Green function method combined with an effective mass theory. We found that the susceptance of a QPC increases stepwise with increasing gate voltage, when the width of the quantization plateau in the gate voltage-conductance curve is narrower than the width of the region where the conductance changes gradually. We also show that the height of a susceptance step is proportional to the ac-bias frequency. These simulation results are in excellent qualitative agreement with recent experimental results. Moreover, we found that the transition from capacitive susceptance to inductive susceptance occurs with increasing gate voltage. The capacitive-inductive transition point is independent of the ac-bias frequency, but it does depend on the contact width.
URI:	http://hdl.handle.net/2241/114019
Rights:	©2011 American Physical Society
Text Version:	publisher
Appears in Collections:	白石賢二 (Shiraishi Kenji) Physical review B

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