TY - JOUR
T1 - Magnon thermal conductivity in the spin-gap state and the antiferromagnetically ordered state of low-dimensional copper oxides
AU - Kudo, K.
AU - Koike, Y.
AU - Kurogi, S.
AU - Noji, T.
AU - Nishizaki, T.
AU - Kobayashi, N.
N1 - Funding Information:
This work was partially supported by The Iwatani Naoji Foundation's Research Grant.
PY - 2004/5
Y1 - 2004/5
N2 - We have looked for large thermal-conductivity due to magnons, k magnon, in various kinds of low-dimensional quantum spin systems, such as the two-leg spin-ladder system Sr14Cu24O 41, the two-dimensional spin-dimer system SrCu2(BO 3)2, the four-leg spin-ladder system La2Cu 2O5, the two-dimensional spin system Cu3B 2O6 and the one-dimensional spin system Ca 2Y2Cu5O10, using large-sized single-crystals grown by the TSFZ method. Large kmagnon has been found in the spin-gap state of Sr14Cu24O41 whose bandwidth of the triplet excitation is large, owing to the enhancement of the mean free path of magnons. In gapless systems, it has been found that K magnon increases with increasing magnon-velocity, which increases with increasing exchange-interaction between Cu2+ spins and is larger in antiferromagnetic spin-correlation systems than in ferromagnetic spin-correlation systems. Therefore, it is concluded that essential factors of large kmagnon are a large bandwidth of the triplet excitation in a spin-gap system, a large exchange-interaction and antiferromagnetic spin-correlation rather than ferromagnetic spin-correlation.
AB - We have looked for large thermal-conductivity due to magnons, k magnon, in various kinds of low-dimensional quantum spin systems, such as the two-leg spin-ladder system Sr14Cu24O 41, the two-dimensional spin-dimer system SrCu2(BO 3)2, the four-leg spin-ladder system La2Cu 2O5, the two-dimensional spin system Cu3B 2O6 and the one-dimensional spin system Ca 2Y2Cu5O10, using large-sized single-crystals grown by the TSFZ method. Large kmagnon has been found in the spin-gap state of Sr14Cu24O41 whose bandwidth of the triplet excitation is large, owing to the enhancement of the mean free path of magnons. In gapless systems, it has been found that K magnon increases with increasing magnon-velocity, which increases with increasing exchange-interaction between Cu2+ spins and is larger in antiferromagnetic spin-correlation systems than in ferromagnetic spin-correlation systems. Therefore, it is concluded that essential factors of large kmagnon are a large bandwidth of the triplet excitation in a spin-gap system, a large exchange-interaction and antiferromagnetic spin-correlation rather than ferromagnetic spin-correlation.
KW - Antiferromagnetic order
KW - Low-dimensional copper oxide
KW - Magnon thermal conductivity
KW - Spin-gap
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U2 - 10.1016/j.jmmm.2003.11.040
DO - 10.1016/j.jmmm.2003.11.040
M3 - Article
AN - SCOPUS:20344376508
VL - 272-276
SP - 94
EP - 95
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
SN - 0304-8853
IS - I
ER -