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arXiv 1202.0220cond-mat.str-el
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Shastry-Sutherland晶格Yb $_{2}$ Pt $_{2}$ Pb中的自旋液体和反铁磁序

Spin Liquids and Antiferromagnetic Order in the Shastry-Sutherland-Lattice Yb$_{2}$Pt$_{2}$Pb

M. S. Kim, M. C. Aronson

摘要:

我们目前的测量的磁化率$χ$和金属\ypp,其中本地化的Yb力矩位于几何挫折Shastry-Sutherland晶格(SSL)的单晶的磁化M。在这个准二维系统中发现了强的磁阻挫,它从Yb-二聚体的顺磁性液体中反铁磁有序排列为T_PDMATHABMO =2.02 \emph{K},在单重基态和三重激发态之间有一个能隙$Δ$ =4.6 \emph{K}.磁场抑制AF阶,其在1.25 \emph{T}量子临界点处消失。自旋间隙$Δ$持续到1.5 \emph{T},表明AF在T=0时退化为二聚体三联体的液体。在AF状态内的M(B)中观察到量化步骤,这是SSL系统的签名。我们的研究结果表明,\ypp是独特的,无论是作为一个金属SSL系统,是接近AF量子临界点,并作为一个重费米子化合物的几何挫折起着决定性的作用。

英文摘要:

We present measurements of the magnetic susceptibility $χ$ and the magnetization M of single crystals of metallic \ypp, where localized Yb moments lie on the geometrically frustrated Shastry-Sutherland Lattice (SSL). Strong magnetic frustration is found in this quasi-two dimensional system, which orders antiferromagnetically (AF) at T$_{N}$=2.02 \emph{K} from a paramagnetic liquid of Yb-dimers, having a gap $Δ$=4.6 \emph{K} between the singlet ground state and the triplet excited states. Magnetic fields suppress the AF order, which vanishes at a 1.25 \emph{T} quantum critical point. The spin gap $Δ$ persists to 1.5 \emph{T}, indicating that the AF degenerates into a liquid of dimer triplets at T=0. Quantized steps are observed in M(B) within the AF state, a signature of SSL systems. Our results show that \ypp is unique, both as a metallic SSL system that is close to an AF quantum critical point, and as a heavy fermion compound where geometrical frustration plays a decisive role.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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