A5000081327- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Machine Learning in Materials Science
- Spectroscopy and Laser Applications
- Quantum, superfluid, helium dynamics
- Quantum Dots Synthesis And Properties
- Catalysis and Oxidation Reactions
- Cold Atom Physics and Bose-Einstein Condensates
- Ion-surface interactions and analysis
- Chalcogenide Semiconductor Thin Films
- Advanced Fiber Laser Technologies
- Topological Materials and Phenomena
- Crystallography and molecular interactions
- Quantum Computing Algorithms and Architecture
- Atomic and Molecular Physics
- Catalytic Processes in Materials Science
- Microbial Metabolism and Applications
- Theoretical and Computational Physics
- Molecular Junctions and Nanostructures
- Analytical Chemistry and Chromatography
- nanoparticles nucleation surface interactions
- Protein purification and stability
- Advanced Materials Characterization Techniques
Microsoft (United States)
2025
Aarhus University
2009-2022
University College London
2013-2021
University of Oxford
2015-2016
Oxford Research Group
2016
A strong inhomogeneous static electric field is used to spatially disperse a supersonic beam of polar molecules, according their quantum state. We show that the molecules residing in lowest-lying rotational states can be selected and as targets for further experiments. As an illustration, we demonstrate unprecedented degree laser-induced one-dimensional alignment $(⟨{cos}^{2}{\ensuremath{\theta}}_{2\mathrm{D}}⟩=0.97)$ orientation state-selected iodobenzene molecules. This method should...
Ab initio kinetic Monte Carlo (KMC) simulations have been successfully applied for over two decades to elucidate the underlying physico-chemical phenomena on surfaces of heterogeneous catalysts. These necessitate detailed knowledge kinetics elementary reactions constituting reaction mechanism, and energetics species participating in chemistry. The information about is encoded formation energies gas surface-bound species, lateral interactions between adsorbates catalytic surface, which can be...
Supersonic beams of polar molecules are deflected using inhomogeneous electric fields. The quantum-state selectivity the deflection is used to spatially separate according their quantum state. A detailed analysis and obtained selection presented. rotational temperatures molecular determined from spatial beam profiles all approximately 1 K. Unprecedented degrees laser-induced alignment (<cos2 theta2D>=0.972) orientation iodobenzene demonstrated when state-selected samples used. Such oriented...
A strong inhomogeneous static electric field is used to spatially disperse a rotationally cold supersonic beam of 2,6-difluoroiodobenzene molecules according their rotational quantum state. The in the lowest lying states are selected and as targets for 3-dimensional alignment orientation. induced adiabatic regime with an elliptically polarized, intense laser pulse orientation by combined action weak field. We show that degree strongly enhanced when state-selected molecules, rather than...
We study how the combination of long and short laser pulses, can be used to induce torsion in an axially chiral biphenyl derivative (3,5-difluoro-3',5'-dibromo-4'-cyanobiphenyl). A long, with respect molecular rotational periods, elliptically polarized pulse produces 3D alignment molecules, a linearly initiates about stereogenic axis. The torsional motion is monitored real-time by measuring dihedral angle using femtosecond time-resolved Coulomb explosion imaging. Within first 4 picoseconds,...
There is currently limited understanding of the role played by haemodynamic forces on processes governing vascular development. One many obstacles to be overcome being able measure those forces, at required resolution level, vessels only a few micrometres thick. In current paper, we present an in silico method for computation experienced murine retinal vasculature (a widely used development animal model) beyond what measurable experimentally. Our results show that it possible reconstruct...
We show that a 450 fs nonresonant, moderately intense, linearly polarized laser pulse can induce field-free molecular axis alignment of methyliodide (${\mathrm{CH}}_{3}\mathrm{I}$) molecules dissolved in helium nanodroplet. Time-resolved measurements reveal rotational dynamics much slower than isolated and absence the sharp transient recurrences characteristic gas phase molecules. Our results presage range new opportunities for exploring both dissipative environment properties He nanodroplets.
The yield of strong-field ionization, by a linearly polarized probe pulse, is studied experimentally and theoretically, as function the relative orientation between laser field molecule. Experimentally, carbonyl sulfide, benzonitrile naphthalene molecules are aligned in one or three dimensions before being singly ionized 30 fs pulse centered at 800 nm. Theoretically, we address behaviour these molecules. We consider degree alignment model angular dependence total ionization molecular...
The torsional motion of a molecule composed two substituted benzene rings, linked by single bond, is coherently controlled pair strong ($3\ifmmode\times\else\texttimes\fi{}1{0}^{13}\text{ }\text{ }\mathrm{W}\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$), nonresonant (800 nm) 200-fs-long laser pulses---both linearly polarized perpendicular to the single-bond axis. If second pulse sent at time when rings rotate toward (away from) each other amplitude torsion strongly enhanced (reduced). persists...
The ``pixel imaging mass spectrometry'' camera is used to perform femtosecond laser-induced Coulomb explosion of 3,5-dibromo-3${}^{\ensuremath{'}}$,5${}^{\ensuremath{'}}$-difluoro-4${}^{\ensuremath{'}}$-cyanobiphenyl molecules prealigned in space. experiment allows the concurrent detection correlated two-dimensional momentum images all ionic fragments resulting from fragmentation multiple each acquisition cycle. studies provide rich information about parent molecular structure and dynamics,...
Keep 'em separated: Stereoisomers of complex molecules generally have very different electric dipole moments for the same mass. The dipole-moment-to-mass ratios can be exploited in separation these species using fields. pure samples thus created offer opportunities isomer-specific and stereoselective investigations.
We present combined experimental and theoretical results on strong-field ionization of oriented carbonyl sulfide molecules by circularly polarized laser pulses. The obtained molecular frame photoelectron angular distributions show pronounced asymmetries perpendicular to the direction electric dipole moment. These findings are explained a tunneling model invoking laser-induced Stark shifts associated with dipoles polarizabilities molecule its unrelaxed cation. focus article is understand...
Femtosecond laser-induced Coulomb-explosion imaging of 3,5-dibromo-$3{}^{\ensuremath{'}},5{}^{\ensuremath{'}}$-difluoro-$4{}^{\ensuremath{'}}$-cyanobiphenyl molecules prealigned in space is explored using a pixel-imaging mass-spectrometry (PImMS) camera. The fast-event-triggered camera allows the concurrent detection correlated two-dimensional momentum images, or covariance maps, all ionic fragments resulting from fragmentation multiple each acquisition cycle. Detailed simulation maps...
We have experimentally and theoretically investigated the mixed-field orientation of rotational-state-selected OCS molecules achieved strong degrees alignment orientation. The applied moderately intense nanosecond laser pulses are long enough to adiabatically align molecules. However, in combination with a weak dc electric field, same result nonadiabatic dynamics These observations fully explained by calculations employing both adiabatic (time-dependent) models.
We make use of an inhomogeneous electrostatic dipole field to impart a quantum-state-dependent deflection pulsed beam OCS molecules, and show that those molecules residing in the absolute ground state, X(1)Σ(+), |00(0)0>, J = 0, can be separated out by selecting most deflected part molecular beam. Past deflector, we irradiate linearly polarized nonresonant laser impulsively aligns molecules. Their alignment, monitored via velocity-map imaging, is measured as function time, time dependence...
Large chiral molecules are aligned and subsequently ``imaged'' after Coulomb explosions by intense, femtosecond laser pulses, unveiling their chirality, which is usually difficult to detect but often leads quite different chemical properties of the molecules.