Spins Made to Order in Low Dimensions
نویسندگان
چکیده
The quantum liquid formed by charge carriers in a conductor is a very excitable system [1]. Besides carrying electric current and screening electromagnetic fields, it can mediate magnetic interactions between stationary microscopic magnetic moments embedded in its host material (such as those from impurities). This so-called Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism [2] arises from a combination of quantum effects. First, the familiar exchange interaction causes a coupling of strength J between any localized magnetic moment Iα and the charge carriers’ spin density S(Rα) at its position Rα. Second, the inherently wavelike properties of itinerant carriers in a conductor then result in a spatially extended magnetization pattern that generates a pairwise exchange interaction between the localized magnetic moments, described formally by an effective spin Hamiltonian
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