Rydberg-Matter and Excited-State Clusters
This is a special issue on Rydberg-Matter and Excited-State Clusters. It contains four invited reviews and six contributed papers. The theme of the invited reviews (and one contributed paper) is Rydberg Matter Clusters while the remaining contributed papers deal with excited-state and/or unusual clusters with interesting properties. Rydberg matter (RM) is an exotic phase (or […]
RARE GAS CLUSTERS Explosions and Dissociations
Clusters containing many identical atoms are of considerable interest because they form a bridge between individual atoms and molecules on the one hand and the bulk solid-state form of matter on the other. Structures of up to many thousands of atoms can be made quite readily and studying them gives some valuable information about how […]
Rydberg Composites
We introduce the Rydberg composite, a new class of Rydberg matter where a single Rydberg atom is interfaced with a dense environment of neutral ground state atoms. The properties of the composite depend on both the Rydberg excitation, which provides the gross energetic and spatial scales, and the distribution of ground state atoms within the […]
Low energy structural dynamics and constrained libration of Li(NH3)4, the lowest melting point metal
The lattice and molecular dynamics for the solid phases of the lowest melting-point metal, Li(NH3)4, are determined by incoherent inelastic neutron scattering. Measurements of internal molecular displacements and distortions of the Li(NH3)4 units have been modelled and assigned using density functional theory calculations for the solid and molecular system. Inelastic neutron scattering measurement allows for […]
Characterizing the excess electron of Li(NH3)4
Small lithium ammonia clusters are model systems for the dissociation of metals into solvated cations and electrons in ammonia. Metal–ammonia solutions display a complex behavior with increasing metal concentration including a phase change from a paramagnetic to a metallic dia- magnetic phase, and small clusters should be useful models in the low concentration regime, where […]
Do not forget the Rydberg orbitals
Within any molecule or cluster containing one or more positively charged sites, families of Rydberg orbitals exist. Free electrons can attach directly, and anionic reagents with low electron binding energy can transfer an electron into one of these orbitals to form a neutral Rydberg radical. The possibilities that such a radical could form a covalent […]
Electronic and vibrational relaxation dynamics of NH3 Rydberg states probed by vacuum-ultraviolet time-resolved photoelectron imaging
Time-resolved dynamics of high-lying Rydberg states of ammonia (NH3) prepared by using a vacuum ultraviolet (VUV) pump (∼9.3 eV) and an ultraviolet (UV) probe (∼4.7 eV) pulse are reported using photoelectron imaging detection. After photoexcitation, two main features appear in the photoelectron spectrum with vertical binding energies of ∼1.8 eV and ∼3.2 eV and with […]
Recent advances in Rydberg physics using alkaline-earth atoms
In this brief review, the opportunities that the alkaline-earth elements offer for studying new aspects of Rydberg physics are discussed. For example, the bosonic alkaline-earth isotopes have zero nuclear spin which eliminates many of the complexities present in alkali Rydberg studies permitting simpler and more direct comparison between theory and experiment. The presence of two valence electrons allows the production of singlet and triplet Rydberg states that can exhibit a variety of attractive or repulsive interactions. The availability of weak intercombination lines is advantageous for laser cooling and for applications such as Rydberg dressing.Excitation of one electron to a Rydberg state leaves behind an optically-active core ion allowing, for high-L states, the optical imaging of Rydberg atoms and their (spatial) manipulation using light scattering. The second valence e. Recent advances in both theory and experiment are highlighted together with a number of possible directions for the future.lectron opens up the possibility of engineering long-lived doubly-excited states such as planetary atoms.
The Rotation and Inversion of Normal and Deuterated Ammonia in Inert Matrices
Infrared spectra have been recorded for all of the vibrational fundamental regions of NH8 in argon, krypton, and xenon matrices, for the VI fundamental region of NH8 in neon and nitrogen matrices, and for the ~2, VP’,a nd ~4” fundamental regions of the deuterated ammonias in an argon matrix. Detailed studies of the temperature and time dependence of absorptions attributed to rotational structure in the vibrational transitions have led to an assignment consistent with almost free rotation of the ammonia molecule in rare gas matrices. The theory of Devonshire has been used to evaluate a barrier to rotation of NH3 in these matrices. The inversion splittings observed for the ~2f undamentals of NJ&, NHzD, and NHDz are somewhat smaller than for the gas-phase molecules, but the calculated inversion potential barrier is increased by only about 10% in the rare gases. No structure in the ~2 spectral region can be attributed to the rotation or inversion of NH-d, in a nitrogen matrix. However, rotation of the molecule about its C3 axis may occur in the nitrogen matrix.
A Condensed Excited (Rydberg) Matter: Perspective and Applications
A condensed excited matter called Rydberg Matter (RM) have been studied experimentally for 30 years, but have not sparked widespread attention yet, unlike ordinary Rydberg atoms. RM formed by clusters of Rydberg atoms at a solid surface have a longer lifetime compared to Rydberg atoms, and is liquid-like. This review describes how the RM state is generated, and its potential applications. These include using RM for research into catalysis, space phenomena and sensor applications, or for producing environmentally friendly energy. A background on RM is presented, with its structure and special properties, and the working principle of RM generation. The experimental set-ups, materials, and detectors used are discussed, together with methods to improve the amount of RM produced. The materials used for the catalysts are of special interest, as this should have a large influence on the energy of the RM, and therefore also on the applications.Currently most of the catalysts used are potassium doped iron oxide designed for styrene production, which should give the possibility of improvements. And as there is little knowledge on the exact mechanisms for RM formation, suggestions are given as to where research should start.