Orphan spins and bound in-gap states in the $S={5over2}$ antiferromagnet CaFe$_{2}$O$_{4}$


الملخص بالإنكليزية

CaFe$_{2}$O$_{4}$ is an anisotropic $S={5over 2}$ antiferromagnet with two competing $A$ ($uparrow uparrow downarrow downarrow$) and $B$ ($uparrow downarrow uparrow downarrow$) magnetic order parameters separated by static antiphase boundaries at low temperatures. Neutron diffraction and bulk susceptibility measurements, show that the spins near these boundaries are weakly correlated and a carry an uncompensated ferromagnetic moment that can be tuned with a magnetic field. Spectroscopic measurements find these spins are bound with excitation energies less than the bulk magnetic spin-waves and resemble the spectra from isolated spin-clusters. Localized bound orphaned spins separate the two competing magnetic order parameters in CaFe$_{2}$O$_{4}$.

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