Paramagnetic spin Hall magnetoresistance

Abstract

Spin Hall magnetoresistance (SMR) refers to a resistance change in a metallic film reflecting the magnetization direction of a magnet attached to the film. The mechanism of this phenomenon is spin exchange between conduction-electron spins and magnetization at the interface. SMR has been used to read out information written in a small magnet and to detect magnetization dynamics, but it has been limited to magnets; magnetic ordered phases or instability of magnetic phase transition has been believed to be indispensable. Here, we report the observation of SMR in a paramagnetic insulator Gd${}_3$Ga${}_5$O${}_{12}$ (GGG) without spontaneous magnetization combined with a Pt film. The paramagnetic SMR can be attributed to spin-transfer torque acting on localized spins in GGG. We determine the efficiencies of spin torque and spin-flip scattering at the Pt/GGG interface, and demonstrate these quantities can be tuned with external magnetic fields. The results clarify the mechanism of spin-transport at a metal/paramagnetic insulator interface, which gives new insight into the spintronic manipulation of spin states in paramagnetic systems.

40 pages, 15 figures

References in corpus (9)

• Spin Transfer Torques
• Theory of spin Hall magnetoresistance
• Non-collinear Magnetoelectronics
• Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO
• Anomalous Hall effect in YIG$|$Pt bilayers
• Control of spin injection by direct current in lateral spin valves
• Interface-dependent magnetotransport properties for thin Pt films on ferrimagnetic Y3Fe5O12
• Control of spin current by a magnetic YIG substrate in NiFe/Al nonlocal spin valves
• Quantifying the spin mixing conductance of EuO/W heterostructures by spin Hall magnetoresistance experiments

Cited by in corpus (5)

• Mechanism of paramagnetic spin Seebeck effect
• Observation of magnetization surface textures of the van der Waals antiferromagnet FePS3 by spin Hall magnetoresistance
• Spin Hall magnetoresistance in paramagnetic NdGaO3
• Observation of quantum interference conductance fluctuations in metal rings with strong spin-orbit coupling
• The spin Hall effect