  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-$\frac{1}{2}$ magnet LiCuVO$_4$, known to
exhibit spin-nematic correlation in a wide range of external magnetic field
$B$. The suppression takes place above $|B| > 2$ T in spite of the $B$-linear
isothermal magnetization curves in the same $B$ range. The result can be
attributed to the growth of the spin-nematic correlation while increasing $B$.
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.
