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“Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots”. Zebrowski DP, Peeters FM, Szafran B, Semiconductor science and technology 32, 065016 (2017). http://doi.org/10.1088/1361-6641/AA6DF4
Abstract: Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.305
DOI: 10.1088/1361-6641/AA6DF4
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“Double quantum dots defined in bilayer graphene”. Zebrowski DP, Peeters FM, Szafran B, Physical review B 96, 035434 (2017). http://doi.org/10.1103/PHYSREVB.96.035434
Abstract: Artificial molecular states of double quantum dots defined in bilayer graphene are studied with the atomistic tight-binding method and its low-energy continuum approximation. We indicate that the extended electron wave functions have opposite parities on sublattices of the layers and that the ground-state wave-function components change from bonding to antibonding with the interdot distance. In the weak-coupling limit, the one most relevant for quantum dots defined electrostatically, the signatures of the interdot coupling include, for the two-electron ground state, formation of states with symmetric or antisymmetric spatial wave functions split by the exchange energy. In the high-energy part of the spectrum the states with both electrons in the same dot are found with the splitting of energy levels corresponding to simultaneous tunneling of the electron pair from one dot to the other.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PHYSREVB.96.035434
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“Exact broken-symmetry states and Hartree-Fock solutions for quantum dots at high magnetic fields”. Szafran B, Peeters FM, Bednarek S, Adamowski J, Physica. E: Low-dimensional systems and nanostructures
T2 –, 3rd International Conference on Quantum Dots (QD 2004), MAY 10-13, 2004, Max Bell Bldg Banff Ctr, Banff, Canada 26, 252 (2005). http://doi.org/10.1016/j.physe.2004.08.059
Abstract: Wigner molecules formed at high magnetic fields in circular and elliptic quantum dots are studied by exact diagonalization (ED) and unrestricted Hartree-Fock (UHF) methods with multicenter basis of displaced lowest Landau level wave functions. The broken symmetry states with semi-classical charge density constructed from superpositions of the ED solutions are compared to the UHF results. UHF overlooks the dependence of the few-electron wave functions on the actual relative positions of electrons localized in different charge puddles and partially compensates for this neglect by an exaggerated separation of charge islands which are more strongly localized than in the exact broken-symmetry states. (C) 2004 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 2
DOI: 10.1016/j.physe.2004.08.059
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“Effective Landé, factors for an electrostatically defined quantum point contact in silicene”. Rzeszotarski B, Mrenca-Kolasinska A, Peeters FM, Szafran B, Scientific Reports 11, 19892 (2021). http://doi.org/10.1038/S41598-021-99074-6
Abstract: The transconductance and effective Lande g* factors for a quantum point contact defined in silicene by the electric field of a split gate is investigated. The strong spin-orbit coupling in buckled silicene reduces the g* factor for in-plane magnetic field from the nominal value 2 to around 1.2 for the first-to 0.45 for the third conduction subband. However, for perpendicular magnetic field we observe an enhancement of g* factors for the first subband to 5.8 in nanoribbon with zigzag and to 2.5 with armchair edge. The main contribution to the Zeeman splitting comes from the intrinsic spin-orbit coupling defined by the Kane-Mele form of interaction.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.259
DOI: 10.1038/S41598-021-99074-6
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