Spin Relaxation of Electrons in Single InAs Quantum Dots

Abstract

By using polarization-resolved photoluminescence spectra, we study the electron spin relaxation in single InAs quantum dots (QDs) with the configuration of positively charged excitons X+ (one electron, two holes). The spin relaxation rate of the hot electrons increases with the increasing energy of exciting photons. For electrons localized in QDs the spin relaxation is induced by hyperfine interaction with the nuclei. A rapid decrease of polarization degree with increasing temperature suggests that the spin relaxation mechanisms are mainly changed from the hyperfine interaction with nuclei into an electron-hole exchange interaction.

Comprehensive Treatment of Coal Waste Piles with Spontaneous Combustion

“…Surface temperature information using by infrared technology or thermometer could be combined with spatial information to set up the surface temperature field of coal waste piles [3][4][5] . According to surface temperature field and the relationship between heat production and heat loss of deep fire point, and considering the characteristics of inhomogeneous porous, the position of deep fire point could be reduced, which use heat conduction model such as temperature gradient, unsteady heat conduction equation, the seepage mathematical model and heat balance method [6][7][8][9][10][11] . It will provide basic information to implement fire prevention and extinguishing accurately and effectively.…”