Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/101769
Title: Local magnetic moments and electronic transport in closed loop quantum dot systems: A case of quadruple quantum dot ring at and away from equilibrium
Authors: Protsenko, V. S.
Katanin, A. A.
Issue Date: 2019
Publisher: American Physical Society
Citation: Protsenko V. S. Local magnetic moments and electronic transport in closed loop quantum dot systems: A case of quadruple quantum dot ring at and away from equilibrium / V. S. Protsenko, A. A. Katanin. — DOI 10.1103/PhysRevB.99.165114 // Physical Review B. — 2019. — Vol. 99. — Iss. 16. — 165114.
Abstract: We apply the nonequilibrium functional renormalization group approach treating flow of the electronic self-energies, to describe local magnetic moment formation and electronic transport in a quadruple quantum dot (QQD) ring, coupled to leads, with moderate Coulomb interaction on the quantum dots. We find that at zero temperature depending on parameters of the QQD system, the regimes with zero, one, or two almost local magnetic moments in the ring can be realized, and the results of the considered approach in equilibrium agree qualitatively with those of a more sophisticated functional renormalization group approach treating also flow of the vertices. It is shown that the almost formed local magnetic moments, which exist in the equilibrium, remain stable in a wide range of bias voltages near equilibrium. The destruction of the local magnetic moments with increasing bias voltage is realized in one or two stages, depending on the parameters of the system; for the two-stage process the intermediate phase possesses fractional magnetic moments. We present zero-temperature results for current-voltage dependencies and differential conductances of the system, which exhibit sharp features at the transition points between different magnetic states. The occurrence of the interaction-induced negative differential conductance phenomenon is demonstrated and discussed. For one local moment in the ring and finite hopping between the opposite quantum dots, connected to the leads, we find suppression of the conductance for one of the spin projections in infinitesimally small magnetic field, which occurs due to destructive interference of different electron propagation paths and can be used in spintronic devices. © 2019 American Physical Society.
Keywords: BIAS VOLTAGE
MAGNETIC FIELDS
MAGNETIC MOMENTS
NANOCRYSTALS
QUANTUM CHEMISTRY
STATISTICAL MECHANICS
DESTRUCTIVE INTERFERENCE
DIFFERENTIAL CONDUCTANCES
ELECTRON PROPAGATION
ELECTRONIC TRANSPORT
FUNCTIONAL RENORMALIZATION GROUP
LOCAL MAGNETIC MOMENTS
NEGATIVE DIFFERENTIAL CONDUCTANCE
QUANTUM DOT SYSTEMS
SEMICONDUCTOR QUANTUM DOTS
URI: http://hdl.handle.net/10995/101769
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 85065127848
PURE ID: 9315742
ISSN: 24699950
DOI: 10.1103/PhysRevB.99.165114
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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