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Magnetic interactions and spin polarized transport in magnetic quantum dots

Grant number: 07/05783-2
Support type:Regular Research Grants
Duration: February 01, 2008 - July 31, 2010
Field of knowledge:Physical Sciences and Mathematics - Physics - Condensed Matter Physics
Principal Investigator:José Carlos Egues de Menezes
Grantee:José Carlos Egues de Menezes
Home Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil


Here we present research plans to investigate quantum transport through a magnetic quantum dot -- with (spin 5/2) Mn impurities embedded and interacting electrons -- coupled to ferromagnetic leads. Basically, we shall investigate the electron-electron interactions effects (i) on the elecron-Mn coupling (i.e.the s-d exchange), (ii) on the Mn-Mn coupling, and (iii) we shall also study how the effects in (i) and (ii) affect, for instance, the resonant tunneling through the quantum dot. We will consider a variety of systems: single dots with several electrons and a single Mn impurity as well as with two impurities, double quantum dots coupled in series and in parallel also containing interacting electrons and one, two or more magnetic impurities. Initially we will study in detail the electronic structure of two-dimensional quantum dots by solving the Schrödinger equation of the system in an appropriate basis ("configuration interaction") via exact diagonalization. From these results we will determine the relevant parameters (e.g., s-d exchange constant and tunneling rates) for the quantum master equation model, directly derived from the Hamiltonian of the system. Possible extensions, generalizations, and additional studies involve, for instance, the inclusion of spin-orbit interaction effects, the calculation of the quantum shot noise, and the determination of the electronic structure of the dots via Spin Density Functional Theory. (AU)

Articles published in Pesquisa FAPESP Magazine about the research grant:
The oscillation of particles