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.
@article{arxiv.2109.00352,
title = {Triplon current generation in solids},
author = {Yao Chen and Masahiro Sato and Yifei Tang and Yuki Shiomi and Koichi Oyanagi and Takatsugu Masuda and Yusuke Nambu and Masaki Fujita and Eiji Saitoh},
journal= {arXiv preprint arXiv:2109.00352},
year = {2021}
}