Study of giant thermal conductivity due to magnons in low-dimensional quantum spin system copper oxides

低维量子自旋体系铜氧化物中磁振子的巨热导率研究

• 批准号: 14340097
• 负责人: KOIKE Yoji
• 金额: $ 10.88万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340097/
• 关键词: quantum spin system; low-dimensional system; thermal conductivity; magnon; spin gap; antiferromagnetism; spin flop transition; Bose-Einstein condensation; 高温超伝導; 磁場誘起磁気秩序; ストライプ秩序; 銅酸化物; 強磁性

We have studied the thermal conductivity and other physical properties of several copper oxides regarded as low-dimensional quantum spin systems, in order to clarify the mechanism of the giant thermal conductivity due to magnons and also to clarify whether the thermal conductivity measurement is powerful for the detection of a phase transition or not.We have discovered large thermal conductivity due to magnons in the four-leg spin-ladder system La_2Cu_2O_5 and the two-dimensional spin system Cu_3B_2O_6.In one-dimensional spin systems Sr_2CuO_3 and SrCuO_2, we have proved from the study of the impurity effects that the thermal conductivity due to magnons is very large and that the thermal conduction is ballistic as theoretically expected.From these results, it has been concluded that both the large antiferromagnetic interaction between spins and the large dispersion of magnons give rise to the large thermal conductivity due to magnons.Moreover, marked changes of the thermal conductivity have been observed at the following phase transitions; the spin-flop transition in the antiferromagnetically ordered state of Ca_2Y_2Cu_5O_<10> and Cu_3B_2O_6, the Bose-Einstein condensation transition off magnons in TlCuCl_3 under high magnetic fields at low temperatures, and the field-induced magnetic order in La_<2-x>Sr_xCUO_4 and La_<2-x>Ba_xCuO_4. Accordingly, we have concluded that the thermal conductivity measurement is a powerful probe to detect and study a phase transition.

我们已经研究了几种被视为低维量子自旋系统的几种铜氧化物的热导率和其他物理特性，以阐明由于镁质引起的巨型导热率的机制，并且还可以阐明导热率测量是否强大，对于相位转换是否强大。二维旋转系统Cu_3b_2o_6.6在一维自旋系统SR_2CUO_3和SRCUO_2中，我们从对杂质导致的杂质电导率的研究中证明了很大，并且在理论上是弹道的。镁的分散剂会引起由于镁引起的较大的热导率。此外，在以下相变处观察到了热导率的明显变化。 CA_2Y__2CU_5O_ <10>和CU_3B_2O_6的抗磁性有序状态中的自旋流动过渡，在高温下，在高温下，在高温下，bose-Einstein凝结在tlcucl_3中的镁质过渡，以及LA________________________________44 la_ <2-x> ba_xcuo_4。因此，我们得出的结论是，导热率测量是检测和研究相变的强大探针。

项目成果

Magnon thermal conductivity in the spin-gap state and the antiferromagnetically ordered state of low-dimensional copper oxides

低维铜氧化物自旋间隙态和反铁磁有序态的磁振子热导率

• 发表时间: 2004
• 期刊: Journal of Magnetism and Magnetic Materials 272-276
• 作者: A.Yamamoto;K.Kudo
• 通讯作者: K.Kudo

Thermal conductivity in the Bose-Einstein condendsed state of TlCuCl_3.

TlCuCl_3 玻色-爱因斯坦凝聚态的热导率。

• 发表时间: 2004
• 期刊: Journal of Magnetism and Magnetic Materials 272-276
• 作者: K.Kudo

Thermal conductivity in low-dimensional quantum spin systems.

低维量子自旋系统中的热导率。

• 发表时间: 2003
• 期刊: Solid State Physics[in Japanese] 38
• 作者: Y.Matsushita;J.Taniguchi;A.Yamaguchi;H.Ishimoto;H.Ikegami;T.Matsushita;N.Wada;S.M.Gatica;M.W.Cole;F.Ancilotto;K.Kudo
• 通讯作者: K.Kudo

Drastic Enhancement of Thermal Conductivity in the Bose-Einstein Condensed State of TlCuCl_3

TlCuCl_3玻色-爱因斯坦凝聚态热导率的显着增强

• 发表时间: 2004
• 期刊: Journal of the Physical Society of Japan 73
• 作者: H.Hashimoto;T.Sashima;K.Yanagi;M.Yoshizawa;K.Kudo
• 通讯作者: K.Kudo

Kazutaka Kudo: "Thermal conductivity of the four-leg spin-ladder system La_2Cu_2O_5 single crystal"Journal of Low Temperature Physics. 131(印刷中). (2003)

工藤一隆：“四腿自旋梯系统La_2Cu_2O_5单晶的热导率”，《低温物理学报》131（出版中）。