Fission widths of hot nuclei from Langevin dynamics

Fission dynamics of excited nuclei is studied in the framework of Langevin equation. The one body wall-and-window friction is used as the dissipative force in the Langevin equation. In addition to the usual wall formula friction, the chaos weighted wall formula developed earlier to account for nonintegrability of single-particle motion within the nuclear volume is also considered here. The fission rate calculated with the chaos weighted wall formula is found to be faster by about a factor of two than that obtained with the usual wall friction. The systematic dependence of fission width on temperature and spin of the fissioning nucleus is investigated and a simple parametric form of fission width is obtained.Comment: RevTex, 12 pages including 9 Postscript figure

Tunable cavity coupling of the zero phonon line of a nitrogen-vacancy defect in diamond

We demonstrate the tunable enhancement of the zero phonon line of a single nitrogen-vacancy color center in diamond at cryogenic temperature. An open cavity fabricated using focused ion beam milling provides mode volumes as small as 1.24 $\mu$m$^3$. In-situ tuning of the cavity resonance is achieved with piezoelectric actuators. At optimal coupling of the full open cavity the signal from individual zero phonon line transitions is enhanced by about a factor of 10 and the overall emission rate of the NV$^-$ center is increased by 40% compared with that measured from the same center in the absence of cavity field confinement. This result is important for the realization of efficient spin-photon interfaces and scalable quantum computing using optically addressable solid state spin qubits.Comment: 11 pages Main Article + 4 pages Supplementary Info Typos fixed from v

Polaron relaxation in self-assembled quantum dots: Breakdown of the semi-classical model

We calculate the lifetime of conduction band excited states in self-assembled quantum dots by taking into account LO-phonon-electron interaction and various anharmonic phonon couplings. We show that polaron relaxation cannot be accurately described by a semi-classical model. The contributions of different anharmonic decay channels are shown to depend strongly on the polaron energy. We calculate the energy dependence of polaron lifetime and compare our results to available experimental measurements of polaron decay time in InAs/GaAs quantum dots.Comment: 5 pages, 4 figure, accepted for publication in Phys. Rev. B (Rapid Com.

Integrating Learning And Visualization Technologies In Orthopaedics:- Establishing The Virtual Orthopaedic European University

Digital technologies offer a working environment for familiarisation with new surgical procedures and management of clinical case audit. Our aim is to provide a novel route for access to educational material that more closely resembles the working practice of the arthroscopist. This is to support higher surgical training and life long learning. The proof of concept has been the development of a shoulder arthroscopy simulation model as an interface for the surgical trainee to access multimedia based educational orthopaedic modules. This demonstrates a human-computer interface that more closely resembles the process of factual knowledge association during clinical procedures, moving toward the ultimate goal of seamless integration of knowledge repositories with clinical intervention operative video information, integrating the structured surgical course model with the multimedia educational orthopaedic modules, generated for the learning of shoulder surgery