Picosecond spin Seebeck effect

TL;DR

This paper demonstrates time-resolved measurements of the spin Seebeck effect at picosecond scales, revealing rapid angular momentum transfer across interfaces in specific material systems.

Contribution

It provides the first direct observation of ultrafast spin Seebeck effect dynamics and quantifies interfacial spin transport properties.

Findings

Angular momentum transfer occurs on a picosecond timescale.

The interfacial spin Seebeck coefficient is of the order of 10^8 A m^{-2} K^{-1}.

Spin-mixing conductance product measured is approximately 10^8 A m^{-2} K^{-1}.

Abstract

We report time-resolved magneto-optic Kerr effect measurements of the longitudinal spin Seebeck effect driven by an interfacial temperature difference between itinerant electrons and magnons. The measured time-evolution of spin accumulation induced by laser-excitation indicates transfer of angular momentum across Au/Y$_3$Fe$_5$O$_{12}$ and Cu/Y$_3$Fe$_5$O$_{12}$ interfaces on a picosecond time-scale. The product of spin-mixing conductance and interfacial spin Seebeck coefficient determined is of the order of $10^8$ A m$^{-2}$ K$^{-1}$.