2002/04/15 by Toshimasa Fujisawa, T. Fujisawa, D. G. Austing +6 · 4 citations
Physics and Astronomy · #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #Surface and Thin Film Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.88.236802
accepted for publication in Phys. Rev.Lett
arxiv created 2002/04/15 · openalex publication_date 2002/05/23 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate nonequilibrium transport in the absence of spin-flip energy relaxation in a few-electron quantum dot artificial atom. Novel nonequilibrium tunneling processes involving high-spin states, which cannot be excited from the ground state because of spin blockade, and other processes involving more than two charge states are observed. These processes cannot be explained by orthodox Coulomb blockade theory. The absence of effective spin relaxation induces considerable fluctuation of the spin, charge, and total energy of the quantum dot. Although these features are revealed clearly by pulse excitation measurements, they are also observed in conventional dc current characteristics of quantum dots.