Interference effects in high-order harmonic generation with molecules

Published versio

Dark States and Coherent Control of Spin States in Molecular Magnets

We propose a scheme to realize coherent control of spin states of molecule magnet, Ni$_4$. We introduce transverse magnetic fields with special frequencies. When the frequencies of transverse magnetic fields match in some conditions, we obtain dark states in Ni$_4$ molecules. Through adjusting the magnitude of magnetic fields, we can obtain any arbitrary superposition of the two ground spin states of Ni$_4$ molecules.Comment: 7 pages, 4 figures. To appear in Physical Review

Electromagnetically induced transparency controlled by a microwave field

We have experimentally studied propagation of two optical fields in a dense rubidium (Rb) vapor in the case when an additional microwave field is coupled to the hyperfine levels of Rb atoms. The Rb energy levels form a close-lambda three-level system coupled to the optical fields and the microwave field. It has been found that the maximum transmission of a probe field depends on the relative phase between the optical and the microwave fields. We have observed both constructive and destructive interference in electromagnetically induced transparency (EIT). A simple theoretical model and a numerical simulation have been developed to explain the observed experimental results.Comment: 7 pages, 6 figure

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10−1 mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer

Probing orbital structure of polyatomic molecules by high-order harmonic generation (vol 98, art no 203007, 2007)

Publisher’s Note: Probing Orbital Structure of Polyatomic Molecules by High-Order Harmonic Generation [Phys. Rev. Lett. 98, 203007 (2007)

Orientation dependence of high-order harmonic generation in molecules

Published versio

An integrative review exploring decision-making factors influencing mental health nurses in the use of restraint

Introduction: While mechanical and manual restraint as an institutional method of control within mental health settings may be perceived to seem necessary at times, there is emergent literature highlighting the potential counter-therapeutic impact of this practice for patients as well as staff. Nurses are the professional group who are most likely to use mechanical and manual restraint methods within mental health settings. In-depth insights to understand what factors influence nurses’ decision-making related to restraint use are therefore warranted. Aim: To explore what influences mental health nurses’ decision-making in the use of restraint. Method: An integrative review using Cooper’s framework was undertaken. Results: Eight emerging themes were identified: ‘safety for all’, ‘restraint as a necessary intervention’, ‘restraint as a last resort’, ‘role conflict’, ‘maintaining control’, ‘staff composition’, ‘knowledge and perception of patient behaviours’, and ‘psychological impact’. These themes highlight how mental health nurses’ decision-making is influenced by ethical and safety responsibilities, as well as, interpersonal and staff-related factors. Conclusion: Research to further understand the experience and actualization of ‘last resort’ in the use of restraint and to provide strategies to prevent restraint use in mental health settings are needed