Electron spin relaxation in InGaAs/InP multiple-quantum wells

Abstract

The electron spin relaxation of InGaAs/InP multiple-quantum wells (MQW) is investigated using time-resolved polarization-dependent absorption measurement. The MQW has an excitonic absorption at 1.54 μm which is suitable for application in optical communications. A theoretical prediction assuming the D’yakonov-Perel’ interaction as the main relaxation mechanism gives a spin relaxation rate for the InGaAs quantum well over twice as high as that for the GaAs quantum well. The spin relaxation time measured at room temperature is 5.2 ps and found to be an order of magnitude faster than that of a GaAs quantum well.

Spin relaxation in n-InSb/AlInSb quantum wells

“…where again C DP is a dimensionless constant, predicted to be 16 [13]. Using equation (2) for InSb, α c = 0.045 which agrees well with other calculations [18].…”

“…It has been shown that for the GaAs/AlGaAs QW system at room temperature the DP process is the dominant spin relaxation mechanism (for example, [13]- [15]), as with the bulk materials. This is also true for the narrow gap system InAs/GaSb (for example [6,16]).…”

“…For small k in bulk crystals this splitting can be written as E = γk 3 , where γ is the Dresselhaus spin splitting coefficient [18]. For QWs, the spin splitting is linear in k and the Rashba coefficient α c , related to the spin splitting, is given by [13]:…”

Zero-field spin splitting and spin lifetime inn−InSb∕In1−xAlxGilbertson1, Fearn2, Jefferson3 et al. 2008Phys. Rev. B

“…This is the D'yakonov-Perel' (DP) spin relaxation mechanism [16], shown to be present in most III-V semiconductor systems over a broad range of temperatures [17,18,19,20]. It is essential for spintronic devices as the dominance of this mechanism is necessary for the gate modulation of spin populations [21].…”

Spin-polarized transport in a two-dimensional electron gas with interdigital-ferromagnetic contacts

“…4 The peak and dip features disappear, however, at a much lower temperature Ϸ10 K. The characteristic difference between our FM1-2DEG-FM2 devices and the FM-2DEG diode device 12 is that we measure ⌬R/R 0 ϭ2 2 exp(ϪL/I s ) ͑Ref. 13͒ which is sensitive to the temperature dependence of the spin-relaxation length l s , 16 while for the diode 12 ⌬R/R 0 ϭ2 P, which is sensitive to the spin- polarization P of the 2DEG. 13 Here, is the parametrized fractional spin polarization of the current crossing the FM-2DEG interface.…”