Details

Autor(en) / Beteiligte

• Lisenkov, Ivan
• Khymyn, Roman
• Åkerman, Johan
• Sun, Nian X.
• Ivanov, Boris A.

Titel

Subterahertz ferrimagnetic spin-transfer torque oscillator

Ist Teil von

• Physical review. B, 2019-09, Vol.100 (10), Article 100409

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2019

Link zum Volltext

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• A theory of magnetization dynamics in ferrimagnetic materials with antiparallel aligned spin sublattices under the action of spin-transfer torques (STTs) is developed. In contrast with antiferromagnets, the magnetic sublattices in ferrimagnets are formed by different magnetic ions, which results in a symmetry breaking in the dynamic equations for Néel's vector. We demonstrate that this symmetry breaking becomes crucially essential for the THz signal extraction in ferrimagnetic spin-torque oscillators. As an example, we consider magnetization dynamics in GdFeCo layers in spin Hall and nanocontact spin-torque oscillator geometries. We demonstrate that (i) the application of spin current leads to a conical precession of Néel's vector with sub-THz frequencies, (ii) in the spin Hall geometry, the conical precession leads to sub-THz oscillations of the Hall voltage, and (iii) in the nanocontact geometry the Néel's vector precession leads to sub-THz oscillations of the magnetoresistance.