Ellipticity and dissipation effects in magnon spin valves

Abstract

We consider alignment-dependent spin and heat transport across a magnon spin valve in the tunneling regime, i.e., a junction consisting of two weakly-coupled ferromagnetic insulators. We determine the difference in spin and heat conductance between the parallel and antiparallel configuration of the magnetization direction. The dependence of these conductances on both the Gilbert damping and ellipticity is studied. We find that both magnon ellipticity and dissipation open channels for magnons to tunnel through in the antiparallel configuration. Our results highlight an important difference between electronic and magnon spin transport in spin-valve structures and may be important for the development of devices based on magnetic insulators. arXiv:1911.12017v1 [cond-mat.mes-hall]

Hydrogenation-induced high-temperature superconductivity in two-dimensional molybdenum carbide Mo2C3

“…Superconductivity remains in (a) E-mail: hylu@qfnu.edu.cn (corresponding author) (b) E-mail: pzhang2012@qq.com the monolayer NbSe 2 with T c of 1.9 K, which has been confirmed in experiment [8]. 2D NiTe 2 was predicted to be an intrinsic superconductors with T c about 5.7 K [9]. Monolayer MoS 2 can also be a superconductor under doping and biaxial strain with T c of 22 K [10].…”

Green's function formalism for nonlocal elliptical magnon transport

“…We may therefore conclude that it arises due to the mismatch between the lead states, where spin is a good quantum number, and the elliptical magnon eigenstates of the anisotropic ferromagnet. Ultimately, the mismatch is necessarily compensated by the lattice [21]. As this term contributes directly to the spin current flowing out of the lead to which a spin bias is applied, it offers a way to probe the ellipticity of magnons through local spin current measurements.…”

“…In this work, however, we explicitly consider the ef-fects of potentially large anisotropies, which break spin conservation and generate elliptically polarized magnons. The breaking of spin conservation is known to give rise to phenomena such as magnon tunneling between weakly coupled ferromagnetic insulators [21], which is prohibited when spin is conserved, and super-Poissonian shot noise [20]. Such phenomena are expected to arise whenever the ferromagnet under consideration has sufficiently strong anisotropy, e.g.…”

Magnonic spin transport in magnetic insulators

“…We may therefore conclude that it arises due to the mismatch between the lead states, where spin is a good quantum number, and the elliptical magnon eigenstates of the anisotropic ferromagnet. Ultimately, the mismatch is necessarily compensated by the lattice [82]. As this term contributes directly to the spin current flowing out of the lead to which a spin bias is applied, it offers a way to probe the ellipticity of magnons through local spin current measurements.…”

“…In this work, however, we explicitly consider the effects of potentially large anisotropies, which break spin conservation and generate elliptically polarized magnons. The breaking of spin conservation is known to give rise to phenomena such as magnon tunneling between weakly coupled ferromagnetic insulators [82], which is prohibited when spin is conserved, and super-Poissonian shot noise [81]. Such phenomena are expected to arise whenever the ferromagnet under consideration has sufficiently strong anisotropy, e.g.…”