title: Resonantly enhanced nonlinear conductance in long quantum point contacts near pinch-off.
abstract: We report on a remarkable resonance in the differential conductance of long quantum point contacts (QPCs) that is observed as a precursor to regular quantized transport. This effect is increasingly pronounced in longer QPCs, in which the differential conductance may resonantly exceed 2e2/h. From a study of the experimental characteristics of this feature, we suggest that it may be associated with the formation of a well-resolved energy gap that opens dynamically as a result of enhanced many-body interactions in long QPCs.
authors.affiliation: Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Morimoto
authors.forename: M
authors.initials: M
authors.lastname: Henmi
authors.forename: R
authors.initials: R
authors.lastname: Naito
authors.forename: K
authors.initials: K
authors.lastname: Tsubaki
authors.forename: N
authors.initials: N
authors.lastname: Aoki
authors.forename: J P
authors.initials: JP
authors.lastname: Bird
authors.forename: Y
authors.initials: Y
authors.lastname: Ochiai