Exploration of the double exchange in quantum cellular automata: proposal for a new class of cellsстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 21 октября 2020 г.
Аннотация:In this communication we propose to considerably extend the class of systems suitable as cells for quantum cellularautomata (QCA) by including magnetic quantum dots and molecular mixed valence dimers exhibiting double exchange. Asdistinguished from the previous works we propose to use not only charges as the information carriers but also spin degreesof freedom. In this context we focus on the two key points: 1) properties of the magnetic cell as reservoir for charges carryingbinary information, and 2) identification of conditions under which spin degrees of freedom can be employed. The adoptedelectronic model of the isolated bi-dimeric cell takes into account ferromagnetic double exchange, antiferromagneticHeisenberg-Dirac-Van Vleck (HDVV) exchange and Coulomb repulsion between the two mobile electrons belonging todifferent dimeric half-cells. The ground spin state of the isolated cell proves to be the result of competition between HDVVexchange and reduced (second-order) double exchange. The polarized driver-cell produces additional antiferromagneticeffect in the working cell by suppressing the residual ferromagnetic double exchange. Under certain conditions the workingcell is shown to exhibit spin-switching.