Physics

Torque

Electron

Spin Hall effect

Spin diffusion

Ferromagnetism

Power (physics)

Spin pumping

Spin polarization

Materials science

Condensed matter physics

Spin (aerodynamics)

Quantum mechanics

Generator (circuit theory)

Thermodynamics

Physical Review Applied

We report very efficient spin current generation by the spin Hall effect in the alloy Au0.25Pt0.75, which, as determined by two different direct spin-orbit torque measurements, exhibits a giant internal spin Hall ratio of > 0.58 (anti-damping spin-orbit torque efficiency of ~ 0.35 in bilayers with Co), a relatively low resistivity of ~ 83 uOhm cm, an exceptionally large spin Hall conductivity of > 7.0x10^5 ohm^-1 m^-1, and a spin diffusion length of 1.7 nm. This work establishes Au0.25Pt0.75 as a milestone spin current generator that provides greater energy efficiency than that yet obtained with other heavy metals or with the topological insulators Bi2Se3 and (Bi,Se)2Te3. Our findings should advance spin-orbit torque-based fundamental research and benefit the development of new fast, efficient spin-orbit torque-driven magnetic memories, skyrmion and chiral domain wall devices, and microwave and terahertz emitters.

Highly Efficient Spin-Current Generation by the Spin Hall Effect in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mi>Au</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Pt</mml:mi><mml:mi>x</mml:mi></mml:msub></mml:math>

Highly Efficient Spin-Current Generation by the Spin Hall Effect in Au1−xPtx