A5075244822- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Information and Cryptography
- Mechanical and Optical Resonators
- Advanced Frequency and Time Standards
- Silicon and Solar Cell Technologies
- Quantum Mechanics and Applications
- Atomic and Subatomic Physics Research
- Photonic and Optical Devices
- Molecular spectroscopy and chirality
- solar cell performance optimization
- Experimental Learning in Engineering
- Advanced MEMS and NEMS Technologies
- Thin-Film Transistor Technologies
- Spectroscopy and Quantum Chemical Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Quantum optics and atomic interactions
- Molecular Junctions and Nanostructures
- Chemical and Physical Properties of Materials
- Photovoltaic System Optimization Techniques
- Strong Light-Matter Interactions
- Autoimmune and Inflammatory Disorders
- Metallurgical and Alloy Processes
- Food, Nutrition, and Cultural Practices
- Engineering Education and Curriculum Development
- Advanced Thermodynamics and Statistical Mechanics
Imperial College London
2012-2024
Northern Sydney Local Health District
2023
University of Strathclyde
2018
Vienna Center for Quantum Science and Technology
2014-2017
University of Vienna
2014-2017
University of Leeds
2008
UNSW Sydney
2002-2006
National Renewable Energy Laboratory
1993
Sandia National Laboratories California
1992
Office of Scientific and Technical Information
1992
Abstract We propose in this White Paper a concept for space experiment using cold atoms to search ultra-light dark matter, and detect gravitational waves the frequency range between most sensitive ranges of LISA terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment Dark Matter Gravity Exploration (AEDGE), will also complement other planned searches exploit synergies with wave detectors. give examples extended sensitivity matter offered...
We present an atom interferometer using large momentum transfer without $k$-reversal. More specifically, we use a microwave $\pi$/2 pulse to manipulate the spin state of $^{87}$Rb atoms before applying Raman light $\pi$ achieve 4$\hbar k$ per pulse. A in middle sequence reverses states, which allows closing arms by same pulses discuss scalability this technique. Our results extend scope optics into interferometers where $k$-reversal are not available.
We investigate the use of a Bose-Einstein condensate trapped on an atom chip for making interferometric measurements small energy differences. measure and explain noise in difference split condensates, which derives from statistical number difference. also consider systematic errors. A leading effect is variation rf magnetic field trap with distance wires surface. This can produce differences that are comparable those due to gravity.
Matter waves pass multipath interference test.
We have integrated magneto-optical traps (MOTs) into an atom chip by etching pyramids a silicon wafer.These been used to trap atoms on the chip, directly from room temperature vapor of rubidium.This new trapping method provides simple way integrate several sources same chip.It represents substantial advance in technology and offers possibilities for applications such as single or photon molecules chip.
It has recently been shown that optical reflection gratings fabricated directly into an atom chip provide a simple and effective way to trap cool substantial clouds of atoms (Nshii et al. in Nat Nanotechnol 8:321–324, 2013; McGilligan Opt Express 23(7):8948–8959, 2015). In this article, we describe how the are designed microfabricated characterise their properties, which determine effectiveness as cold source. We use scalar diffraction theory understand morphology determines power diffracted beams.
We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto dilute molecular beam through quantum interference. As crosses light field probe laser some will absorb single photon. These events impart momentum recoil which shifts position molecule relative to unperturbed beam. Averaging over shifted and unshifted components within leads reduction fringe visibility, enabling be extracted with high...
Abstract It has recently been shown that matter‐wave interferometry can be used to imprint a periodic nanostructure onto molecular beam, which provides highly sensitive tool for beam displacement measurements. Herein, we this feature measure electronic properties of provitamin A, vitamin E, and K1 in the gas phase first time. The shift fringes static electric field encodes susceptibility time‐averaged dynamic dipole moment. dependence fringe pattern on intensity central light‐wave...
We investigate the operation of pyramidal magneto-optical traps (MOTs) microfabricated in silicon. Measurements loading and loss rates give insight into role nearby surface MOT dynamics. Studies fluorescence versus laser frequency intensity allow us to develop a simple theory operation. The number $^{85}$Rb atoms trapped pyramid is approximately $L^6$, where $L \lesssim 6$ size mm. This follows quite naturally from relation between capture velocity differs $L^{3.6}$ often used describe...
Laser based processing has been incorporated into many successful solar cell technologies over the past 20 years; for example buried contact cells, laser-fired back contacts and laser texturing. However, impact of crystal damage generated during on performance is still uncertain. This paper investigates laser-induced defects that result from a ablation process similar to used form grooves in cell. The first part this focuses formation uses Yang etching technique investigate chemical thermal...
Abstract Matter-wave interferometry can be used to probe the foundations of physics and enable precise measurements particle properties fundamental constants. It relies on beam splitters that coherently divide wave function. In atom interferometers, such elements are often realised using lasers by exploiting dipole interaction or through photon absorption. is intriguing extend these ideas complex molecules where energy an absorbed rapidly redistributed across many internal degrees freedom....
Inertial sensors that measure the acceleration of ultracold atoms promise unrivalled accuracy compared to classical equivalents. However, atomic systems are sensitive various perturbations, including magnetic fields, which can introduce measurement inaccuracies. To address this challenge, we have designed, manufactured, and validated a field stabilisation system for quantum sensor based on atom interferometry. We solve generated by surface currents in-between pair bi-rectangular coils...
Amino acids are essential building blocks of life, and fluorinated derivatives have gained interest in chemistry medicine. Modern mass spectrometry has enabled the study oligo- polypeptides as isolated entities gas phase, but predominantly singly or even multiply charged species. While laser desorption neutral peptides into adiabatically expanding supersonic noble jets is possible, UV-VIS spectroscopy, electric magnetic deflectometry well quantum interferometry would profit from possibility...
Miniature concave hollows, made by wet etching silicon through a circular mask, can be used as mirror substrates for building optical micro-cavities on chip. In this paper we investigate how ICP polishing improves both shape and roughness of the substrates. We characterise evolution surfaces during using white-light profilometry atomic force microscopy. A surface 1 nm is reached, which reduces to 0.5 after coating with high reflectivity dielectric. With such smooth mirrors, cavity finesse...
We define a quantum witness for high-mass matter-wave interferometers that allows us to test fundamental assumptions of macroscopic realism. propose an experimental realization using absorptive laser gratings and show such systems can strongly violate macrorealistic quantum-witness equality. The measurement the therefore provide clear evidence physics beyond macrorealism macromolecules nanoparticles.
We have measured the damped motion of a trapped Bose–Einstein condensate, oscillating with respect to thermal cloud. The cigar-shaped trapping potential provides enough transverse confinement that dynamics system are intermediate between three-dimensional and one-dimensional. find scaling damping rate temperature is consistent Landau theory, but for axial oscillations at given consistently smaller than expected gas. attribute this suppressed density states low-energy excitations (essential...
Laser doping is investigated as an alternative to high-temperature furnace diffusions form contacts on bifacial n-type silicon solar cells. A process demonstrated in which a single laser step forms both selective heavily doped contact regions and defines mask for subsequent electro-less metal plating. The integration of the with cell structures terms minority carrier recombination, plating electrical properties finished devices. shown be promising may provide more industrially applicable...
We propose an optical grating for matter waves that separates molecules depending on whether their interaction with the light is conservative or dissipative. Potential applications include fundamental tests of quantum mechanics, measurement molecular properties, and ability to selectively prepare different internal temperatures.
We have studied the surface quality of millimeter-scale optical mirrors produced by etching CZ and FZ silicon wafers in potassium hydroxide to expose $\{111\}$ planes. find that surfaces four times lower noise power at spatial frequencies up $500\, {mm}^{-1}$. conclude made using higher quality.
We consider the positions and velocities of electrons spinning nuclei demonstrate that these particles harbour hidden momentum when located in an electromagnetic field. This is present all atoms molecules, however it ultimately canceled by point out electron vortex electric field might a comparatively large recognize phenomenon momentum.
We give an explicit and general description of the energy, linear momentum, angular momentum boost a molecule to order 1/c2, where it necessary take account kinetic contributions made by electrons nuclei as well electromagnetic intramolecular field. A wealth interesting subtleties are encountered that not seen at 1/c0, including relativistic Hall shifts, anomalous velocities hidden momenta. Some these have known analogues in solid state physics.
March 2000 marked the commencement of what is believed to be world's first Bachelor Engineering in Photovoltaics (PV) and Solar Energy. The new program has been implemented at University New South Wales. It particularly strong support from industry, end users, Australian government host institution. explosive growth PV industry responsible for triggering these high levels educational area. degree popular. Forty-one students have commenced program, with most having university acceptance index...