Unidirectional Spin-Wave-Propagation-Induced Seebeck Voltage in a PEDOT:PSS/YIG Bilayer

Abstract

We clarify the physical origin of the dc voltage generation in a bilayer of a conducting polymer film and a micrometer-thick magnetic insulator Y_{3}Fe_{5}O_{12} (YIG) film under ferromagnetic resonance and/or spin wave excitation conditions. The previous attributed mechanism, the inverse spin Hall effect in the polymer [Nat. Mater. 12, 622 (2013)NMAACR1476-112210.1038/nmat3634], is excluded by two control experiments. We find an in-plane temperature gradient in YIG which has the same angular dependence with the generated voltage. Both vanish when the YIG thickness is reduced to a few nanometers. Thus, we argue that the dc voltage is governed by the Seebeck effect in the polymer, where the temperature gradient is created by the nonreciprocal magnetostatic surface spin wave propagation in YIG.

Spin-orbit torque and Nernst effect in Bi-Sb/Co heterostructures

“…For example, Yasuda et al [34] have discussed how asymmetric magnon scattering could influence the magnitude of the spin Hall angle. Similarly, it has been observed recently that the Seebeck effect can be a spurious signal in spin-pumping experiments [35]. From both the points of view of understanding the underlying physics and its ultimate adoption for an application, it is important to identify the sources of spurious signals in the quantification of the spin Hall angle.…”

Broadband Nonreciprocity Enabled by Strong Coupling of Magnons and Microwave Photons

“…There, spin waves propagating in cavity and described by quantum electrodynamics (QED) demonstrate a good tunability thus having high potential for quantum applications at macroscopic scale [18,21]. Along the similar path, the nonreciprocity of magnons, which has been observed and utilized for coherent information processing [22][23][24][25], can be brought into microwave electrodynamics through hybridization. Yet, non-reciprocity has not been reported in hybrid magnonmicrowave photon systems until very recently [26].…”

Chiral Coupling to Magnetodipolar Radiation

“…Bulk volume modes and surface (Damon-Eshbach) modes propagate along or perpendicular to the magnetization direction with different dispersion relations [30][31][32][33]. Moreover, the surface modes are chiral: their propagation direction (linear momentum) is fixed by the outer product of surface normal and magnetization direction, allowing unidirectional spin current generation by dominantly exciting one surface of a magnetic film [34][35][36][37]. However, Damon-Eshbach spin waves are not well suited for applications -their group velocity tends to be zero when the linear momentum is larger than the inverse of film thickness, leading to a small spin conductivity.…”