Correlation between electron spin relaxation time and hetero-interface roughness in (1 1 0)-oriented GaAs/AlGaAs multiple-quantum wells

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 41; no. 5; pp. 870 - 875
• Main Authors: Iba, Satoshi, Fujino, Hiroshi, Fujimoto, Toshiyasu, Koh, Shinji, Kawaguchi, Hitoshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2009; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth interruption; Hetero-interface; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum wells; Spin relaxation; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); 78.47.+p; Spin relaxation; quantum wells; 72.25.Rb; Hetero-interface; 78.67.De; Growth interruption; Polarization; Gallium arsenides; Photoluminescence; Roughness; Aluminium Gallium Arsenides Mixed; Multiple quantum well; Time resolved spectra; Interfaces; Temperature effects; Molecular beam epitaxy; Heterostructures
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2009.01.009

The correlation between the electron spin relaxation time τ s and the hetero-interface roughness in (1 1 0)-oriented GaAs/AlGaAs multiple-quantum wells (MQWs) was investigated using growth interruption during molecular beam epitaxy growth. τ s was characterized using polarization- and time-resolved PL measurements, and the hetero-interface roughness was evaluated by the full-width-at-half-maximum of the PL spectra at 4 K. It was found that τ s in the MQWs with smooth interfaces became longer and the temperature dependence of τ s changed from τ s ∼ T 0.6– T 0.9 when the interface roughness was reduced using growth interruption. These results indicate that the structure inversion asymmetry term of the D’yakonov-Perel’ mechanism was suppressed in the MQWs with smooth hetero-interfaces.