Magnon pairs and spin-nematic correlation in the spin Seebeck effect

Hirobe, Daichi*; Sato, Masahiro*; Hagihara, Masato*   ; Shiomi, Yuki*; Masuda, Takatsugu*; Saito, Eiji

Investigating exotic magnetic materials with spintronic techniques is effective at advancing magnetism as well as spintronics. In this work, we report unusual field-induced suppression of the spin Seebeck effect (SSE) in a quasi-one-dimensional frustrated spin- magnet LiCuVO, known to exhibit spin-nematic correlation in a wide range of external magnetic field . The suppression takes place above T in spite of the -linear isothermal magnetization curves in the same range. The result can be attributed to the growth of the spin-nematic correlation while increasing . The correlation stabilizes magnon pairs carrying spin 2, thereby suppressing the interfacial spin injection of SSE by preventing the spin-1 exchange between single magnons and conduction electrons at the interface. This interpretation is supported by integrating thermodynamic measurements and theoretical analysis on the SSE.