Chen Yao, Sato Masahiro, Tang Yifei, Shiomi Yuki, Oyanagi Koichi, Masuda Takatsugu, Nambu Yusuke, Fujita Masaki, Saitoh Eiji
Institute for Materials Research, Tohoku University, Sendai, Japan.
Department of Physics, Ibaraki University, Mito, Ibaraki, Japan.
Nat Commun. 2021 Aug 31;12(1):5199. doi: 10.1038/s41467-021-25494-7.
A triplon refers to a fictitious particle that carries angular momentum S=1 corresponding to the elementary excitation in a broad class of quantum dimerized spin systems. Such systems without magnetic order have long been studied as a testing ground for quantum properties of spins. Although triplons have been found to play a central role in thermal and magnetic properties in dimerized magnets with singlet correlation, a spin angular momentum flow carried by triplons, a triplon current, has not been detected yet. Here we report spin Seebeck effects induced by a triplon current: triplon spin Seebeck effect, using a spin-Peierls system CuGeO. The result shows that the heating-driven triplon transport induces spin current whose sign is positive, opposite to the spin-wave cases in magnets. The triplon spin Seebeck effect persists far below the spin-Peierls transition temperature, being consistent with a theoretical calculation for triplon spin Seebeck effects.
三激子指的是一种虚拟粒子，其携带的角动量S = 1，对应于一大类量子二聚化自旋系统中的基本激发。这类没有磁有序的系统长期以来一直被作为自旋量子特性的试验场进行研究。尽管已发现三激子在具有单重态关联的二聚化磁体的热学和磁学性质中起着核心作用，但由三激子携带的自旋角动量流，即三激子流，尚未被检测到。在此，我们报告了利用自旋 - 派尔斯系统CuGeO由三激子流诱导产生的自旋塞贝克效应：三激子自旋塞贝克效应。结果表明，加热驱动的三激子输运诱导出的自旋流其符号为正，这与磁体中的自旋波情况相反。三激子自旋塞贝克效应在远低于自旋 - 派尔斯转变温度时依然存在，这与三激子自旋塞贝克效应的理论计算结果一致。
