Spin-gap evolution upon Ca doping in the spin-ladder series Sr(14−x)CaxCu24O41 studied by inelastic neutron scattering
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Date
2013-07-03
Journal Title
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Publisher
Americal Physical Society
Abstract
The spin-gap evolution upon Ca doping in Sr14-xCaxCu24O41 was systematically investigated using inelastic neutron scattering. We discover that the singlet-triplet spin-gap excitation survives in this series with x up to 13, indicating the singlet dimer ground state in these compounds. This observation corrects the previous speculation that the spin gap collapses at x similar to 13 by the NMR technique. The strong intensity modulation along Q(H) in x = 0 gradually evolves into a Q-independent feature in x > 11. This could be attributed to the localized Cu moment magnetism developing into an itinerant magnetism with increasing x. It is a surprise that the spin gap persists in the normal state of this spin-ladder system with metallic behavior, which evidences the possibility of magnetically mediated carrier pairing mechanism in a two-leg spin-ladder lattice. © 2013, American Physical Society.
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Keywords
Calcium, Copper, Strontium, Neutrons, Scattering, Spin
Citation
Deng, G., Tsyrulin, N., Bourges, P., Lamago, D., Ronnow, H., Kenzelmann, M., Danilkin, S., Pomjakushina, E., & Conder, K. (2013). Spin-gap evolution upon Ca doping in the spin-ladder series Sr(14−x)CaxCu24O41 studied by inelastic neutron scattering. Physical Review B, 88 (1), 014504. doi:10.1103/PhysRevB.88.014504