title: Charge frustration in a triangular triple quantum dot.
abstract: We experimentally investigate the charge (isospin) frustration induced by a geometrical symmetry in a triangular triple quantum dot. We observe the ground-state charge configurations of sixfold degeneracy, the manifestation of the frustration. The frustration results in omnidirectional charge transport, and it is accompanied by nearby nontrivial triple degenerate states in the charge stability diagram. The findings agree with a capacitive interaction model. We also observe unusual transport by the frustration, which might be related to elastic cotunneling and the interference of trajectories through the dot. This work demonstrates a unique way of studying geometrical frustration in a controllable way.
authors.affiliation: Department of Physics, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: M
authors.initials: M
authors.lastname: Seo
authors.affiliation: Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: H K
authors.initials: HK
authors.lastname: Choi
authors.affiliation: Department of Physics, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Korea Research Institute of Standard and Science, Daejeon 306-600, Republic of Korea.
authors.forename: N
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Physics, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Chung
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors.forename: H-S
authors.initials: HS
authors.lastname: Sim
authors.affiliation: Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: V
authors.initials: V
authors.lastname: Umansky
authors.affiliation: Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Mahalu