2014/07/31 by Kentaro Kitagawa, Yutaka Kishimoto, Kitagawa, K. +19
Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.1407.8274
openalex publication_date 2014/07/31 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present a new type of quantum critical material YbCo2Ge4, having the largest quantum-critical pseudospin size ever. The YbCo2Ge4-type structure is new, forms in the orthorhombic Cmcm system, and is related to the well-known ThCr2Si2 structure. Heavy rare earth (Tm,Yb,Lu, or Y) members are also possible to be grown. YbCo2Ge4 possesses the Ising-type ground-state doublet, namely the simplest ones of uniaxially up or down, |± ∼ 7/2⟩. It is clearly manifested through comprehensive resistivity, magnetization, specific heat, and NQR/NMR experiments. Large pseudospin state usually tends to order in simple magnetisms, or hard to be screened by Kondo effect. Therefore, the discovery of the quantum criticality of the fluctuating large spins opens a new door to new-material search and theoretical studies.