Hysteretic response of electron-nuclear spin system in single InAlAs quantum dots:Excitation power and polarization dependences - Condensed Matter > Materials ScienceReport as inadecuate




Hysteretic response of electron-nuclear spin system in single InAlAs quantum dots:Excitation power and polarization dependences - Condensed Matter > Materials Science - Download this document for free, or read online. Document in PDF available to download.

Abstract: We report the hysteresis of optically-pumped nuclear spin polarization andthe degree of circular polarization of photoluminescence on the excitationpower and electron spin polarization in single InAlAs quantum dots. Byincreasing or decreasing the excitation power at a particular excitationpolarization, an abrupt rise or drop and a clear hysteretic behavior wereobserved in the Overhauser shift of the photoluminescence of the exciton andexciton complexes from the same single quantum dot under an external magneticfield of 5 T. However, the degree of circular polarization shows differentbehaviors between a positively charged exciton and a neutral exciton orbiexciton; further, only positively charged exciton exhibits the preciselysynchronized change and hysteretic behavior. It is suggested that the electronspin distribution is affected by the flip-flop of electron-nuclear spins.Further, the hysteresis is observed as a function of the degree of circularpolarization of the excitation light and its dependence on the excitation poweris studied. The saturation of the Overhauser shift after the abrupt riseindicates the almost complete cancellation of the external magnetic field bythe nuclear field created within the width that is decided by the correlationtime between the electron and the nuclei spin system.



Author: R Kaji, S Adachi, H Sasakura, S Muto

Source: https://arxiv.org/



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