Triplon current generation in solids

Authors
Yao Chen, Masahiro Sato, Yifei Tang, Yuki Shiomi, Koichi Oyanagi,Takatsugu Masuda, Yusuke Nambu, Masaki Fujita, & Eiji Saitoh

Abstract
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 CuGeO₃. 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.


Nature Communications : https://www.nature.com/articles/s41467-021-25494-7