Spin current noise of the spin Seebeck effect and spin pumping

Abstract

We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal metal (NM)/ferromagnet (FM) bilayer system. Starting with a simple FI--NM interface model with both spin-conserving and spin-non-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI--NM coupling strength, and estimate them for an yttrium iron garnet (YIG) --platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon, modified by the spin-non-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.

5 pages, 3 figures

References in corpus (9)

• Spin Seebeck insulator
• Observation of the Spin-Seebeck Effect in a Ferromagnetic Semiconductor
• Theory of magnon-driven spin Seebeck effect
• Enhanced DC Spin Pumping into a Fluctuating Ferromagnet near Tc
• Two-electron bunching in transport through a QD induced by Kondo correlations
• Theory of spin Peltier effect
• Shot Noise Induced by Nonequilibrium Spin Accumulation
• Spin Hall noise
• Noise in mesoscopic physics

Cited by in corpus (9)

• Magnon-squeezing as a niche of quantum magnonics
• Microscopic theory of spin transport at the interface between the superconductor and a ferromagnetic insulator
• Ferromagnetic resonance modulation in $d$-wave superconductor/ferromagnetic insulator bilayer systems
• Spin current at a magnetic junction as a probe of the Kondo state
• Unified formulation of interfacial magnonic pumping from non-collinear magnets
• Non-symmetric spin-pumping in a multiferroic heterostructure
• Detecting Spin Transport in Quantum Magnets with Photons
• Alternating Current-induced Interfacial Spin-transfer Torque
• Universal $1/3$-suppression of magnonic shot noise in diffusive insulating magnets