Quantum Magnetic Properties in Perovskite with Anderson Localized Artificial Spin-1/2
Sprache des Titels:
Englisch
Original Kurzfassung:
Quantum magnetic properties in a geometrically frustrated lattice of spin-
1/2 magnet, such as quantum spin liquid or solid and the associated spin
fractionalization, are considered key in developing a new phase of matter. The
feasibility of observing the quantum magnetic properties, usually found in
geometrically frustrated lattice of spin-1/2 magnet, in a perovskite material
with controlled disorder is demonstrated. It is found that the controlled
chemical disorder, due to the chemical substitution of Ru ions by Co-ions,
in a simple perovskite CaRuO3 creates a random prototype configuration of
artificial spin-1/2 that forms dimer pairs between the nearest and further
away ions. The localization of the Co impurity in the Ru matrix is analyzed
using the Anderson localization formulation. The dimers of artificial spin-1/2,
due to the localization of Co impurities, exhibit singlet-to-triplet excitation
at low temperature without any ordered spin correlation. The localized
gapped excitation evolves into a gapless quasi-continuum as dimer pairs
break and create freely fluctuating fractionalized spins at high temperature.
Together, these properties hint at a new quantum magnetic state with strong
resemblance to the resonance valence bond system.