We investigate the Kondo effect and spin blockade observed in a many-electron quantum dot and study the magnetic field dependence. At lower fields, a pronounced Kondo effect is found, which is replaced by the spin blockade at higher fields. In an intermediate regime, both effects are visible. We make use of this combined effect to gain information about the internal spin configuration of our quantum dot. We find that the data cannot be explained assuming regular filling of electronic orbitals. Instead, spin polarized filling seems to be probable.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.96.046802 | DOI Listing |
Nanoscale Adv
January 2025
Université de Lorraine, CNRS, LRGP F-54000 Nancy France
Water-dispersible core/shell CuInZnSe/ZnS (CIZSe/ZnS) quantum dots (QDs) were efficiently synthesized under microwave irradiation using -acetylcysteine (NAC) and sodium citrate as capping agents. The photoluminescence (PL) emission of CIZSe/ZnS QDs can be tuned from 593 to 733 nm with varying the Zn : Cu molar ratio in the CIZSe core. CIZSe/ZnS QDs prepared with a Zn : Cu ratio of 0.
View Article and Find Full Text PDFNarra J
December 2024
Research Group of Pharmaceutics, School of Pharmacy, Institut Teknologi Bandung, Bandung, Indonesia.
Zebrafish serve as a pivotal model for bioimaging and toxicity assessments; however, the toxicity of banana peel-derived carbon dots in zebrafish has not been previously reported. The aim of this study was to assess the toxicity of carbon dots derived from banana peel in zebrafish, focusing on two types prepared through hydrothermal and pyrolysis methods. Banana peels were synthesized using hydrothermal and pyrolysis techniques and then compared for characteristics, bioimaging ability, and toxicity in zebrafish as an animal model.
View Article and Find Full Text PDFThe construction of an admirable hybrid bulk-heterojunction (HBH) can benefit the performance of optoelectronic devices through efficient charge separation and transportation. However, the present HBH structure still suffers from complicated layer-by-layer ligand exchanges during device fabrication. In this work, we apply a liquid phase exchange strategy in mixed colloidal hybrids composed of quantum dots (QDs) and nanotetrapods (NTs) and construct low-cost flexible self-powered infrared photodetectors with a carbon electrode.
View Article and Find Full Text PDFFabry-Perot (FP) lasers with a cavity length shorten down to 50 µm were investigated. One or two laser mirrors were formed by focused ion beam etching. InGaAs quantum dots of high density were used as the laser active region.
View Article and Find Full Text PDFThe extreme electromagnetic near-field environment of nanoplasmonic resonators and metamaterials can give rise to unprecedented electromagnetic heating effects, enabling large and manipulable temperature gradients on the order of 10-10 K/nm. In this Letter, by interfacing traditional semiconductor quantum dots with industry-grade plasmonic transducer technology, we demonstrate that the near-field-induced thermal gradient can facilitate the requisite population inversion for coherent phonon amplification and lasing at the nanoscale. Our detailed analysis uncovers both the characteristics and parameter sensitivity of inversion and relaxation oscillations in the system, thereby unveiling hitherto unexplored opportunities for leveraging plasmonic near-field effects in the context of quantum thermodynamics and phononics.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!