title: Low-temperature fate of the 0.7 structure in a point contact: a Kondo-like correlated state in an open system.
abstract: Besides the usual conductance plateaus at multiples of 2e(2)/h, quantum point contacts typically show an extra plateau at approximately 0.7(2e(2)/h), believed to arise from electron-electron interactions that prohibit the two spin channels from being simultaneously occupied. We present evidence that the disappearance of the 0.7 structure at very low temperature signals the formation of a Kondo-like correlated spin state. Evidence includes a zero-bias conductance peak that splits in a parallel field, scaling of conductance to a modified Kondo form, and consistency between peak width and the Kondo temperature.
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Cronenwett
authors.forename: H J
authors.initials: HJ
authors.lastname: Lynch
authors.forename: D
authors.initials: D
authors.lastname: Goldhaber-Gordon
authors.forename: L P
authors.initials: LP
authors.lastname: Kouwenhoven
authors.forename: C M
authors.initials: CM
authors.lastname: Marcus
authors.forename: K
authors.initials: K
authors.lastname: Hirose
authors.forename: N S
authors.initials: NS
authors.lastname: Wingreen
authors.forename: V
authors.initials: V
authors.lastname: Umansky