The origin of the non-Fermi liquid state on heavy-fermion Ce compounds

重费米子 Ce 化合物非费米液态的起源

• 批准号: 12640350
• 负责人: TANIGUCHI Toshifumi
• 金额: $ 2.3万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640350/
• 关键词: Ce(Ru, Rh)_2Si_2; scaling law; Quantum fluctuation; Griffiths phase; disorder; non-Fermi liquid; Quantum phase transition; Ce (Ru, Rh)_2Si_2; スケーリング; Griffith相; Ce(Ru,Rh)_2Si_2

In accordance with the plans,(1) Single crystals, Ce(Ru_<1-x>Rh_x)_2Si_2 for x = 0.4, 0.5 and 0.6, were made.(2) An ac susceptibility measurement system was made, which works in the temperature range down to 50 mK and in the magnetic field up to 6 T.We found the ac susceptibilities under magnetic fields χ(T,H) can be expressed by the scaling law as the following.χ(T,H) = T^γf(H/T^δ) (T<1K, H<0.1T)The values of indexes γ, δ of x = 0.5 are different from those of x = 0.6. The scaling law suggests the origin of the non-Fermi liquid behavior in Ce(Ru_<1-x>Rh_x)_2Si_2 is the critical phenomena of the phase transition at T = 0 K. The spin at Ce atom in the mixed compound has good Ising character due to the doublet ground state and has a high Kondo temperature, and the disorder due to the Rh substitution is introduced. Quantum Griffiths phase at T = 0 K can be expected under such a situation. Our results strongly suggest the origin of the non-Fermi liquid behavior is the critical phenomena of the phase transition to quantum Griffiths phase at T = 0 K.

（1）制备了Ce（Ru_<1-x>Rh_x）_2Si_2（x = 0.4，0.5和0.6）单晶。(2)我们研制了一套交流磁化率测量系统，其工作温度范围为50 mK，磁场范围为6 T，我们发现在磁场下的交流磁化率可用标度律χ（T，H）= T^γf（H/T^δ）表示（T&lt;1 K，H&lt;0.1T）x = 0.5和x = 0.6时的γ、δ值不同。标度律表明Ce（Ru_ Rh_x）_2Si_2的非费米液体行为<1-x>起源于T = 0 K相变的临界现象。混合化合物中Ce原子的自旋具有良好的Ising特性，并具有较高的近藤温度，同时引入了Rh取代引起的无序.在这种情况下，可以预期T = 0 K时的量子格里菲斯相。我们的研究结果强烈地表明，非费米液体行为的起源是在T = 0 K时相变到量子Griffiths相的临界现象。

项目成果

H.W.Gn: "Pressure effect on the specific heat and electrical resistance in the Ce(Ru_<0.6>Rh_<0.4>)_2Si_2 compound"Physica B. (未定). (2002)

H.W.Gn：“压力对 Ce(Ru_<0.6>Rh_<0.4>)_2Si_2 化合物中比热和电阻的影响”Physica B. (TBD)。

H.Gu: "Pressure effect on the specific heat and electrical resistance in the Ce(Ru_<0.6>Rh_<0.4>)_2Si_2"Physica. B(未定). (2002)

H.Gu：“压力对 Ce(Ru_<0.6>Rh_<0.4>)_2Si_2 中比热和电阻的影响”Physica B(2002)。

Y. Tabata, T. Taniguchi, Y. Yamamoto, Y. Miyako, M. Ocio, P. Pari and J. Hammann: "Field effect on the non-Fermi-liquid behavior"Physica B. 281&282. 349 (2000)

Y. Tabata、T. Taniguchi、Y. Yamamoto、Y. Miyako、M. Ocio、P. Pari 和 J. Hammann：“非费米液体行为的场效应”Physica B. 281

Y. Miyako, Y. Yamamoto, Y. Tabata, K. Marumoto, M. Sato, T. Taniguchi, T. Takeuchi, S. Kawarazaki, H. Amitsuka, M. Ocio, P. Pari and J. Hammann: "Spin Fluctuations and Anitiferromagnetic Phase Transitions in Heavy Fermions of Kramers (Ce compound) and Non

Y. Miyako、Y. Yamamoto、Y. Tabata、K. Marumoto、M. Sato、T. Taniguchi、T. Takeuchi、S. Kawarazaki、H. Amitsuka、M. Ocio、P. Pari 和 J. Hammann：“Spin

T.Taniquchi: "Non-linear suoceptibilities of Ce (Ru0.5Rh0.5)_2Si_2 and CeGus5.9Au0.1"Physica. 8281&282. 349-350 (2000)

T.Taniquchi：“Ce (Ru0.5Rh0.5)_2Si_2 和 CeGus5.9Au0.1 的非线性感受性”物理学。