Details

Autor(en) / Beteiligte

• Chang, Ting-Yu
• Cheng, Chih-Lin
• Huang, Chao-Chung
• Peng, Cheng-Wei
• Huang, Yu-Hao
• Chen, Tian-Yue
• Liu, Yan-Ting
• Pai, Chi-Feng

Titel

Large unidirectional magnetoresistance in metallic heterostructures in the spin transfer torque regime

Ist Teil von

• Physical review. B, 2021-07, Vol.104 (2), p.1, Article 024432

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2021

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• A large unidirectional magnetoresistance (UMR) ratio of UMR/Rxx ≈ 0.36 % is found in W/CoFeB metallic bilayer heterostructures at room temperature. Three different regimes in terms of the current dependence of the UMR ratio are identified: a spin-dependent-scattering mechanism regime at small current densities J ≈ 109 A / m2 (UMR ratio ∝ J ), a spin-magnon-interaction mechanism regime at intermediate J ≈ 1010 A/m2 (UMR ratio ∝ J3), and a spin transfer torque (STT) regime at J ≈ 1011 A/m2 (UMR ratio independent of J). We verify the direct correlation between this large UMR and the transfer of spin angular momentum from the W layer to the CoFeB layer by both field-dependent and current-dependent UMR characterizations. Numerical simulations further confirm that the large STT-UMR stems from the tilting of the magnetization affected by the spin Hall effect-induced STTs. An alternative approach to estimate dampinglike spin torque efficiencies from magnetic heterostructures is also proposed.