Rydberg matter—A long-lived excited state of matter

Abstract

The theory of condensed excited matter, the so-called Rydberg matter (RM), is examined briefly. Explicit results are given for several physical quantities, notably, the work function and the resistivity, for which experimental results exist. The most important aspects of the experiments, which are fully described elsewhere, are discussed. Large densities of Rydberg species are formed in the experiments with cesium vapor in contact with carbon (graphite) surfaces. The resistivity of the RM formed is found to be 10−2–10−3 Ω·m under varying conditions, while theory gives the order of 10−3 Ω·m. The work function is experimentally found to be less than 0.7 eV, perhaps even less than 0.5 eV. Two different methods were used to extract this quantity from thermionic diode data. These work function values are much lower than reported for any known material, especially at the high temperatures, and they thus give strong support for the description of RM as a very dilute metal. Theory gives values ranging from 0.6 down to 0.2 eV, depending on the principal quantum number, which is estimated to be n=12–14 from the lifetime calculations and from the known pressure. Supporting evidence is found from spectroscopic studies of RM, from jellium calculations, and from recent confirming experiments. From the good agreement between theory and experiment we conclude that RM exists.