Hysteretic response of electron-nuclear spin system in single InAlAs quantum dots:Excitation power and polarization dependences

Abstract

We report the hysteresis of optically-pumped nuclear spin polarization and the degree of circular polarization of photoluminescence on the excitation power and electron spin polarization in single InAlAs quantum dots. By increasing (or decreasing) the excitation power at a particular excitation polarization, an abrupt rise (or drop) and a clear hysteretic behavior were observed in the Overhauser shift of the photoluminescence of the exciton and exciton complexes from the same single quantum dot under an external magnetic field of 5 T. However, the degree of circular polarization shows different behaviors between a positively charged exciton and a neutral exciton or biexciton; further, only positively charged exciton exhibits the precisely synchronized change and hysteretic behavior. It is suggested that the electron spin distribution is affected by the flip-flop of electron-nuclear spins. Further, the hysteresis is observed as a function of the degree of circular polarization of the excitation light and its dependence on the excitation power is studied. The saturation of the Overhauser shift after the abrupt rise indicates the almost complete cancellation of the external magnetic field by the nuclear field created within the width that is decided by the correlation time between the electron and the nuclei spin system.

4 pages, 4 figures

References in corpus (8)

• Optical pumping of electronic and nuclear spin in single charge-tunable quantum dots
• Long-lived memory for mesoscopic quantum bits
• Nuclear Spin Switch in Semiconductor Quantum Dots
• Bistability of the Nuclear Polarisation created through optical pumping in InGaAs Quantum Dots
• Nonlinear dynamics of quantum dot nuclear spins
• Polarization-dependent shift in excitonic Zeeman splitting of self-assembled InAlAs quantum dots
• Photon-spin qubit-conversion based on Overhauser shift of Zeeman energies in quantum dots
• Precise measurements of electron and hole g-factors of single quantum dots by using nuclear field

Cited by in corpus (8)

• Nuclear spin physics in quantum dots: an optical investigation
• General theory of feedback control of a nuclear spin ensemble in quantum dots
• Fine structure and optical pumping of spins in individual semiconductor quantum dots
• Investigation of in-plane nuclear field formation in single self-assembled quantum dots
• Nuclear spin polarization in a single quantum dot pumped by two laser beams
• Third Stable Branch and Tristability of Nuclear Spin Polarization in Single Quantum Dot System
• P-shell carriers assisted dynamic nuclear spin polarization in single quantum dots at zero external magnetic field
• Discretizing the Bistability of Mode-Locked Electron Spin Precession: An Overhauser Field Hysteresis Manifestation