Related papers: Femtosecond photoexcitation dynamics inside a quan…
We have performed quantum Monte Carlo simulations measuring the finite size and temperature superfluid response of helium-4 to the linear and rotational motion of the walls of a nanopore. Within the two-fluid model, the portion of the…
Quantum coherence between electronic states of a photoionized molecule and the resulting process of ultrafast electron-hole migration have been put forward as a possible quantum mechanism of charge-directed reactivity governing the…
Following the changes in molecular structure throughout the entirety of a chemical reaction with atomic resolution is a long-term goal in femtochemistry. Although the development of a plethora of ultrafast technique has enabled detailed…
A multi-cell He gas-scintillator active target, designed for the measurement of photoreaction cross sections, is described. The target has four main chambers, giving an overall thickness of 0.103 $\mathrm{g/cm^{2}}$ at an operating pressure…
The competition between electron localization and de-localization in Mott insulators underpins the physics of strongly-correlated electron systems. Photo-excitation, which re-distributes charge between sites, can control this many-body…
When a chemical bond is broken, the molecular structure undergoes a transformation. An ideal experiment should probe the change in the electronic and nuclear structure simultaneously. Here, we present a method for the simultaneous…
Highly intense, sub-picosecond terahertz (THz) pulses can be used to induce ultrafast temperature jumps (T-jumps) in liquid water. A supercritical state of gas-like water with liquid density is established, and the accompanying structural…
Like many quantum fluids, superfluid helium-4 (He II) can be considered as a mixture of two miscible fluid components: an inviscid superfluid and a viscous normal fluid consisting of thermal quasiparticles [1]. A mutual friction between the…
Photoelectron emission from excited states of laser-dressed atomic helium is analyzed with respect to laser intensity-dependent excitation energy shifts and angular distributions. In the two-color XUV (exteme ultra\-violet) -- IR (infrared)…
We introduce a model description of a diatomic molecule in an optical cavity, with pump and fluorescent fields, and electron and nuclear motion are treated on equal footing and exactly. The model accounts for several optical response…
Glass forming liquids exhibit structural relaxation behaviors, reflecting underlying atomic rearrangements on a wide range of timescales. These behaviors play a crucial role in determining many material properties. However, the relaxation…
We present a novel method to measure transient photovoltage at nanointerfaces using ultrafast electron diffraction. In particular, we report our results on the photoinduced electronic excitations and their ensuing relaxations in a…
For the development of long-distance quantum networks, sources of single photons and entangled photon pairs emitting in the low-loss wavelength region around 1550 nm are a crucial building block. Here we show that quantum dot devices based…
We present a quantum Monte Carlo study of the structure and energetics of silver doped helium clusters AgHe$_n$ for $n$ up to 100. Our simulations show the first solvation shell of the Ag atom to be composed by roughly 20 He atoms, and to…
Bubble nucleation in liquid confined in nanochannel is studied using molecular dynamics simulations and compared against nucleation in the liquid over smooth (i.e. without confinement). Nucleation is achieved by heating part of a surface to…
We study the interaction of strong femtosecond laser pulses with the C$_{60}$ molecule employing time-dependent density functional theory with the ionic background treated in a jellium approximation. The laser intensities considered are…
We have investigated the formation of helium droplets in two physical situations. In the first one, droplets are atomised from superfluid or normal liquid by a fast helium vapour flow. In the second, droplets of normal liquid are formed…
Helium excimers generated by a corona discharge were investigated in the gas and normal liquid phases of helium as a function of temperature and pressure between 3.8 and 5.0 K and 0.2 and 5.6 bar. Intense fluorescence in the visible region…
Interfaces between molecules and 2D materials exhibit energy-driven functionalities, wherein charge transfer directs molecular motion. Unlike equilibrium systems, where molecular assemblies settle into static configurations, continuous…
Progress in electron-beam spectroscopies has recently enabled the study of optical excitations with combined space, energy and time resolution in the nanometer, millielectronvolt and femtosecond domain, thus providing unique access into…