Optical manipulation of electron spin coherence in colloidal CdS quantum dots

Feng, Donghai; Shan, Li; Jia, Tianqing; Pan, Xiaoqing; Tong, Haifang; Deng, Li; Sun, Zhenrong; Xu, Zhujing

doi:10.1063/1.4791790

Cited by 18 publications

(17 citation statements)

References 28 publications

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“…The sizes of CQDs are as small as a few nanometers, leading to strong carrier localization. II–VI CQDs such as CdSe and CdS have been revealed to have long-lived room-temperature electron spin coherence. − Because of a large surface-to-volume ratio and an effective surface interaction with the surroundings, surface conditions in CQDs might have strong influences on the spin decoherence (dephasing) and relaxation processes. However, such influences have not yet been demonstrated.…”

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confidence: 99%

Hole-Acceptor-Manipulated Electron Spin Dynamics in CdSe Colloidal Quantum Dots

Zhang

et al. 2021

J. Phys. Chem. Lett.

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Electron spin dynamics in CdSe quantum dots with hole acceptors are investigated by time-resolved ellipticity spectroscopy. Two types of hole acceptors, Li[Et 3 BH] and 1-octanethiol, result in distinctly different electron spin dynamics. The differences include electron g factors, spin dephasing/relaxation times, and mechanisms. In CdSe quantum dots with Li[Et 3 BH], the electron spin dephasing and relaxation are dominated by electron−nuclear hyperfine interactions in zero and weak magnetic fields. In contrast, hyperfine interactions, electron carrier lifetimes, and exchange interactions between electrons and holes or surface dangling bond spins control the electron spin dynamics in CdSe quantum dots with 1octanethiol. Inhomogeneous dephasing limits the spin coherence time in larger transverse magnetic fields for both hole acceptor cases, but with distinct different g-factor inhomogeneity. These findings manifest that surface conditions play an important role in the spin dynamics and that thereby the surface and its surroundings can be exploited to control the spin in colloidal nanostructures.

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confidence: 99%

Hole-Acceptor-Manipulated Electron Spin Dynamics in CdSe Colloidal Quantum Dots

Zhang

et al. 2021

J. Phys. Chem. Lett.

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“…Algunos de los sistema estudiados con la rotación de Faraday son: la relajación del espín en pozos cuánticos magnéticos [32], la dinámica del espín en los cristales iónicos YAG Ce 3+ [33,34], la preseción del espín en ortoferritas [35] y la coherencia del espín en puntos cuánticos en CdS coloidal [36].…”

Section: 2unclassified

“…Some special cases emerging from these Hamiltonians have been studied by diverse mathematical methods. For instance, the time dependent linear potential has been treated through the Lewis and Riesenfeld 34 invariant theory, 28,29,36 Feynman's path integrals, [37][38][39][40][41] Similar to nitrogen-vacancy centers in diamond and impurity atoms in silicon, interstitial gallium deep paramagnetic centers in GaAsN have been proven to have useful characteristics for the development of spintronic devices. Among other interesting properties, under circularly polarized light, gallium centers act as spin filters that dynamically polarize free and bound electrons reaching record spin polarizations (close to 100%).…”

Section: Introductionmentioning

confidence: 99%

Detección del flip-flop de los centros paramagnéticos del GaAsN mediante bombeo óptico en régimen pulsado

Santana

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“…Room-temperature environment in spin manipulations would be of great interest for future practical device applications. The spin coherence amplitude in colloidal CdS QDs could be easily manipulated by a prepump or control laser pulse with femtosecond pulse durations [ 17 ], which further makes CdS QD materials attractive in spin studies.…”

Section: Introductionmentioning

confidence: 99%

Room-Temperature Electron Spin Generation by Femtosecond Laser Pulses in Colloidal CdS Quantum Dots

et al. 2013

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We present an experimental investigation of optical spin orientation in colloidal CdS quantum dots (QDs) by a femtosecond laser pulse at room temperature. The spin carrier and its spin-generation process are clarified. Firstly, the observed spin signals of CdS QDs in time-resolved Faraday rotation measurements are shown to belong to electron carriers, by comparing the spin dephasing dynamics and Landé g factor between CdS QDs and bulk materials. Secondly, spin dynamics unaffected by the faster carrier recombination suggests that the spin-polarized electrons are not photoexcited but resident in the dots. Moreover, hole spins should dephase very fast compared with electron spins, otherwise the trion (two electrons with opposite spin orientations and one hole) recombination process will affect the resident electron spin signals. The electron spin is generated in a short time of which the excitation light is absorbed and the resident electron is excited to trion states, i.e., of pulse durations. Due to fast hole spin dephasing, trion recombination gives null spin signals, and the subsequent electron spin dynamics is controlled by its intrinsic mechanisms.

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Optical manipulation of electron spin coherence in colloidal CdS quantum dots

Cited by 18 publications

References 28 publications

Hole-Acceptor-Manipulated Electron Spin Dynamics in CdSe Colloidal Quantum Dots

Hole-Acceptor-Manipulated Electron Spin Dynamics in CdSe Colloidal Quantum Dots

Detección del flip-flop de los centros paramagnéticos del GaAsN mediante bombeo óptico en régimen pulsado

Room-Temperature Electron Spin Generation by Femtosecond Laser Pulses in Colloidal CdS Quantum Dots

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