Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Room temperature spin diffusion in (110) GaAs/ AlGaAs quantum wells | Hu et al. Nanoscale Research Letters 2011 6 149 http content 6 1 149 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Room temperature spin diffusion in 110 GaAs AlGaAs quantum wells 2 2 2 12 2 Changcheng Hu 1 2 Huiqi Ye Gang Wang Haitao Tian Wenxin Wang Wenquan Wang 1 Baoli Liu Xavier Marie3 Abstract Transient spin grating experiments are used to investigate the electron spin diffusion in intrinsic 110 GaAs AlGaAs multiple quantum well at room temperature. The measured spin diffusion length of optically excited electrons is about 4 pm at low spin density. Increasing the carrier density yields both a decrease of the spin relaxation time and the spin diffusion coefficient Ds. Introduction The interest in the spin properties of carriers in semiconductors has increased dramatically in the past 10 years due to potential application in the field of spintronics 1 2 . The design of practical spintronic devices usually requires efficient spin injection in the semiconductor long carrier spin lifetimes and long spin trans-port diffusion lengths 3-7 . One of the key parameters describing the properties of carrier spin transport in semiconductors is the spin diffusion coefficient Ds which is often assumed to be the same as charge diffusion coefficient Dc 8 . A direct optical measurement of the electron spin diffusion coefficient can be performed by creating electron spin grating in time-resolved four-wave mixing experiments 9 . This powerful transient spin grating TSG technique was used recently to study the spin transport properties and determine the spin diffusion coefficient Ds 9-11 . In particular it was demonstrated theoretically and experimentally that the spin diffusion coefficient Ds in u-doped 100 -grown GaAs qu antum wells can be smaller than the charge diffusion coefficient Dc due to Coulomb interaction among the electrons the so-called Spin Coulomb Drag effect 10 12 . In these 100 -grown GaAs quantum wells .
