Quantum confinement leads to the emergence of several magnon modes in ultrathin layered magnetic structures. We probe the lifetime of these quantum confined modes in a model system composed of three atomic layers of Co grown on different surfaces. We demonstrate that the quantum confined magnons exhibit nonlinear decay rates, which strongly depend on the mode number, in sharp contrast to what is assumed in the classical dynamics. Combining the experimental results with those of linear-response density-functional calculations we provide a quantitative explanation for this nonlinear damping effect. The results provide new insights into the decay mechanism of spin excitations in ultrathin films and multilayers and pave the way for tuning the dynamical properties of such structures.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.126.177203 | DOI Listing |
Chem Asian J
January 2025
JNCASR: Jawaharlal Nehru Centre for Advanced Scientific Research, New Chemistry Unit, Jakkur, 560064, Bangalore, INDIA.
This study investigates the photophysical behaviour of Mn/Fe and Mn/Sn co-doped CsPbCl3 perovskite nanocrystals (NCs) to explore carrier dynamics and dopant interactions. Using gated photoluminescence (PL) and temperature-dependent measurements, we elucidate the impact of dopant chemistry on exciton behaviour, focusing on vibrationally assisted delayed fluorescence (VADF) and energy transfer mechanisms. The efficiency of VADF is influenced by factors such as the bandgap, temperature, quantum confinement, and host composition.
View Article and Find Full Text PDFEur Phys J B
January 2025
Department of Physics "A. Pontremoli", University of Milan, Via Celoria 16, 20133 Milan, Italy.
Abstract: Quantum rings have emerged as a playground for quantum mechanics and topological physics, with promising technological applications. Experimentally realizable quantum rings, albeit at the scale of a few nanometers, are 3D nanostructures. Surprisingly, no theories exist for the topology of the Fermi sea of quantum rings, and a microscopic theory of superconductivity in nanorings is also missing.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Physics, Government General Degree College Gopiballavpur-II, Jhargram 721517, India.
Effective engineering of nanostructured materials provides a scope to explore the underlying photoelectric phenomenon completely. A simple cost-effective chemical reduction route is taken to grow nanoparticles of Cd Zn S with varying = 1, 0.7, 0.
View Article and Find Full Text PDFLangmuir
January 2025
The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Cluster luminescent materials (CLgens) with nonconjugated structures have attracted considerable attention. However, their low quantum yield and limited emission wavelengths, which are confined to the blue-green spectrum, continue to restrict their applicability. In this study, maleic anhydride polymer chains were modified with -tristyrylene-1,2-diamine (TPM-NH), creating a secondary donor-acceptor structure through freely rotatable phenyl groups and amino-anhydride interactions.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Wide Bandgap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an, 710071, China.
The multiple exciton generation (MEG) effect, which produces multiple photo-generated charge carriers from a single high-energy photon absorption by a semiconductor with a narrow bandgap, has the potential to revolutionize photovoltaic, photoelectric detection, and other technologies. Here, this work finds that the surface carbon-modified wide-bandgap photoanode with hierarchical quantum structure can drive a photoelectrochemical reaction with a quantum efficiency exceeding 145% by the first time. More studies reveal that the presence of the MEG effect in the MEG-CdS photoanode is attributed to the formation of high-quality surface C-modified CdS quantum nanosheets on CdS bulk film by in situ, this hierarchical quantum structure leads to quantum confinement effects that increase effective Coulomb interaction for driving MEG and decrease competition for thermal exciton cooling.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!