On the magnetic excitation spectra of high-Tc Cu oxides at energies up to the region far above the resonance energy

Satoshi Iikubo, Masafumi Ito, Akito Kobayashi, Masatoshi Sato, Kazuhisa Kakurai

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6 Citations (Scopus)

Abstract

The magnetic excitation spectra χ″(q,ω) of YBa 2Cu3Oy and La214 systems have been studied. For a sample of the latter system, La1.88Sr0.12CuO 4, χ″(q,ω) has been measured up to ∼30 meV. Existing data of these two kinds of system have been analyzed at energies up to the values far above ωr, around which χ″(q,ω) exhibits the commensurate peak. In the analyses, we have used the phenomenological expression of the generalized magnetic susceptibility χ(q,ω) = χ0(q,ω)/{1 + J(q) χ0(q, ω)}, where χ0(q,ω) is the susceptibility of the electrons without the exchange coupling J(q) among them. In the energy region up to ∼ωr, it has been reported by the authors' group that the expression can explain the characteristics of the q- and ω-dependences of the spectra of YBa2Cu3Oy (YBCO or YBCO y). Here, it is also pointed out that the expression can reproduce the rotation of the four incommensurate peaks of χ″(q,ω) within the a*-b* plane about (π/a, π/a) [or so-called (π,π)] point by 45°, which occurs as ω goes to the region far above ωr from an energy below ωr. This indicates that for the rotation, "stripe" correlation is not required. For La214, the observed and calculated results of χ″(q,ω) are comparatively discussed up to the ω region far above ωr. These results indicate that for YBCO, the characteristics of χ″(q,ω) can be explained qualitatively by the above expression throughout the ω region studied, while for the La214 system, effects of "stripes" on χ″(q,ω), which cannot be explained by the expression, are more significant in the low-energy region of ω (< ωr) than at high energies.

Original languageEnglish
Pages (from-to)275-278
Number of pages4
Journaljournal of the physical society of japan
Volume74
Issue number1
DOIs
Publication statusPublished - Jan 2005
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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