Delay of Spatial Quantum Correlations in Magnetic Nanostructures

Journal of Experimental and Theoretical Physics. 2020. Vol. 130. No. 4. P. 549–554.

Barabanenkov M. Y., Kalyabin D., Nikitov S.

Simultaneous quantum correlations between two spins in magnetic nanostructures are considered in the model of a linear chain of a finite number of atoms with exchange interaction between electron spins of neighboring atoms in the framework of the Heisenberg ferromagnetism theory. We assume that in the initial state, the spins of all chain atoms except the first two are oriented along the same direction. The spins of the first two atoms are flipped. Due to the exchange interaction, this initial state generates a spin flip wave along the chain. The expressions obtained for nonstationary quantum amplitudes of the flip probability waves for an even number of spins can be used for calculating quantum correlations between two spins separated by a large distance in a chain. Numerical calculations of the spin correlator reveal that the correlation between two spins in the chain occurs with a delay on the order of the time of propagation of the exchange interaction along the spin chain. After the delay, the spin correlation amplitude abruptly increases followed by subsequent oscillatory temporal behavior.

Keywords: ферромагнетики, magnetic nanostructures, магнитные наноструктуры, ferromagnets, quantum correlations, квантовые корреляции