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.

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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.

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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.

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Molecules mimicking atoms: Monomers and dimers of alkali metal solvated electron precursors

Tetra-amino lithium and sodium complexes M(NH3)40,− (M=Li, Na) have one or two electrons that occupy diffuse orbitals distributed chiefly outside the M(NH3)4+ core. The lowest- energy 1s, 1p, and 1d orbitals follow Aufbau principles found earlier for beryllium tetra- ammonia complexes. Two ground state M(NH3)4 complexes can bind covalently by coupling their 1s1 electrons into a σ-type molecular orbital. The lowest excited states of the [M(NH3)4]2 species are obtained by promoting one or two electrons from this σ to other bonding or anti- bonding σ and π-type molecular orbitals. The electronic structure of solvated electron precursors provides insights into chemical bonding between super-atomic species that are present in concentrated alkali-metal-ammonia solutions.

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