A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3701894 | PMC |
| http://dx.doi.org/10.1038/srep02150 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The role of non-invasive stress testing in the diagnosis of coronary microvascular disease.
Cardiovasc Revasc Med
December 2024
Department of Cardiology, Tel Aviv Sourasky Medical Center, affiliated with the School of Medicine, Tel Aviv University, Israel.
Background: Angina with non-obstructive coronary artery disease (ANOCA) is commonly observed in patients with stable angina undergoing coronary angiography. Current guidelines recommend non-invasive stress testing as the first step in diagnosing coronary microvascular disease (CMD). This study aims to evaluate the diagnostic value of non-invasive stress testing in patients invasively diagnosed with CMD.
View Article and Find Full Text PDFQuantum-limited stochastic optical neural networks operating at a few quanta per activation.
Nat Commun
January 2025
School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
Energy efficiency in computation is ultimately limited by noise, with quantum limits setting the fundamental noise floor. Analog physical neural networks hold promise for improved energy efficiency compared to digital electronic neural networks. However, they are typically operated in a relatively high-power regime so that the signal-to-noise ratio (SNR) is large (>10), and the noise can be treated as a perturbation.
View Article and Find Full Text PDFGiant Thermoelectric Response of Fluxons in Superconductors.
Phys Rev Lett
December 2024
Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
We investigate the thermoelectric response of an Abrikosov vortex in type-II superconductors in the deep quantum limit. We consider two thermoelectric geometries, a type-II superconductor-insulator-normal-metal (S-I-N) junction and a local scanning tunneling microscope (STM)-tip normal metal probe over the superconductor. We exploit the strong breaking of particle-hole symmetry in vortex-bound states at subgap energies within the superconducting vortex to realize a giant thermoelectric response in the presence of fluxons.
View Article and Find Full Text PDFExponentially Enhanced Scheme for the Heralded Qudit Greenberger-Horne-Zeilinger State in Linear Optics.
Phys Rev Lett
December 2024
Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea and Division of Quantum Information Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea.
High-dimensional multipartite entanglement plays a crucial role in quantum information science. However, existing schemes for generating such entanglement become complex and costly as the dimension of quantum units increases. In this Letter, we overcome the limitation by proposing a significantly enhanced linear optical heralded scheme that generates the d-level N-partite Greenberger-Horne-Zeilinger (GHZ) state with single-photon sources and linear operations.
View Article and Find Full Text PDFGrating-based x-ray dark-field mammography: Assessing complementary imaging information in simple cystic lesions and typical fibroadenoma.
Med Phys
January 2025
Breast Imaging Department, Red Cross Hospital Munich, Munich, Germany.
Background: A significant proportion of false positive recalls of mammography-screened women is due to benign breast cysts and simple fibroadenomas. These lesions appear mammographically as smooth-shaped dense masses and require the recalling of women for a breast ultrasound to obtain complementary imaging information. They can be identified safely by ultrasound with no need for further assessment or treatment.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!