Effect of picosecond strain pulses on thin layers of the ferromagnetic semiconductor (Ga,Mn)(As,P)

• Published in: Physical review. B, Condensed matter and materials physics Vol. 82; no. 10
• Main Authors: Thevenard, L., Peronne, E., Gourdon, C., Testelin, C., Cubukcu, M., Charron, E., Vincent, S., Lemaître, A., Perrin, B.
• Format: Journal Article
• Language: English
• Published: American Physical Society 17-09-2010
• Subjects: Condensed Matter; Materials Science; Physics; Acoustic propreties of solid; Faraday rotation; Picosecond techniques; Magnetic semiconductors
• ISSN: 1098-0121; 1550-235X
• DOI: 10.1103/PhysRevB.82.104422

The effect of picosecond acoustic strain pulses (ps-ASP) on a thin layer of (Ga,Mn)As codoped with phosphorus was probed using magneto-optical Kerr effect (MOKE). A transient MOKE signal followed by low-amplitude oscillations was evidenced, with a strong dependence on applied magnetic field, temperature, and ps-ASP amplitude. Careful interferometric measurement of the layer’s thickness variation induced by the ps-ASP allowed us to model very accurately the resulting signal, and interpret it as the strain modulated reflectivity (differing for σ± probe polarizations), independently from dynamic magnetization effects.