title: Pseudospin-resolved transport spectroscopy of the Kondo effect in a double quantum dot.
abstract: We report measurements of the Kondo effect in a double quantum dot, where the orbital states act as pseudospin states whose degeneracy contributes to Kondo screening. Standard transport spectroscopy as a function of the bias voltage on both dots shows a zero-bias peak in conductance, analogous to that observed for spin Kondo in single dots. Breaking the orbital degeneracy splits the Kondo resonance in the tunneling density of states above and below the Fermi energy of the leads, with the resonances having different pseudospin character. Using pseudospin-resolved spectroscopy, we demonstrate the pseudospin character by observing a Kondo peak at only one sign of the bias voltage. We show that even when the pseudospin states have very different tunnel rates to the leads, a Kondo temperature can be consistently defined for the double quantum dot system.
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: S
authors.initials: S
authors.lastname: Amasha
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Keller
authors.affiliation: Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: I G
authors.initials: IG
authors.lastname: Rau
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 96100, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Carmi
authors.affiliation: HGST, San Jose, California 95135, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Katine
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 96100, Israel.
authors.forename: Hadas
authors.initials: H
authors.lastname: Shtrikman
authors.affiliation: Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 96100, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Oreg
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA and Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 96100, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Goldhaber-Gordon