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arXiv · 2310.16543

Controllable magnetic states in chains of coupled phi-0 Josephson junctions with ferromagnetic weak links

G. A. Bobkov·I. V. Bobkova·A. M. Bobkov
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Abstract

A superconductor/ferromagnet/superconductor Josephson junction with anomalous phase shift (phi_0-S/F/S JJ) is a system, where the anomalous ground state shift phi_0 provides a direct magnetoelectric coupling between a magnetic moment and a phase of the superconducting condensate. If a chain of such phi_0-S/F/S JJs are coupled via superconducting leads, the condensate phase, being a macroscopic quantity, mediates a long-range interaction between the magnetic moments of the weak links. We study static and dynamic magnetic properties of such a system. It is shown that it manifests properties of n-level system, where the energies of the levels are only determined by projections of the total magnetic moment onto the easy magnetic axis. It is similar to a magnetic atom in a Zeeman field, but the role of the field is played by the magnetoelectric coupling. However, unlike an atom in a magnetic field, the relative order of energies of different states is controlled by electrical means. It is also demonstrated that the total magnetic moment can be fully controlled by a supercurrent and the response of the magnetic system to local external perturbations is highly nonlocal.

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G. A. Bobkov, I. V. Bobkova, A. M. Bobkov. 2023-10-25. Controllable magnetic states in chains of coupled phi-0 Josephson junctions with ferromagnetic weak links. https://doi.org/10.1103/physrevb.109.054523

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