Rydberg atoms states

The ES-mechanism of Frenkel-pair formation as a result of excitation of Rydberg atomic states was confirmed by recent molecular dynamics calculations [28,29]. After the bubble formation the surrounding ground state atoms appear to have moved to the second shell. It was found that the second-nearest neighboring vacancy-interstitial pairs could create the permanent defects, which remain in the lattice after exciton annihilation (Fig.Sb) [29],... 

A term that is nearly synonymous with complex numbers or functions is their phase. The rising preoccupation with the wave function phase in the last few decades is beyond doubt, to the extent that the importance of phases has of late become comparable to that of the moduli. (We use Dirac s terminology [7], which writes a wave function by a set of coefficients, the amplitudes, each expressible in terms of its absolute value, its modulus, and its phase. ) There is a related growth of literatm e on interference effects, associated with Aharonov-Bohm and Berry phases [8-14], In parallel, one has witnessed in recent years a trend to construct selectively and to manipulate wave functions. The necessary techifiques to achieve these are also anchored in the phases of the wave function components. This bend is manifest in such diverse areas as coherent or squeezed states [15,16], elecbon bansport in mesoscopic systems [17], sculpting of Rydberg-atom wavepackets [18,19], repeated and nondemolition quantum measurements [20], wavepacket collapse [21], and quantum computations [22,23], Experimentally, the determination of phases frequently utilizes measurement of Ramsey fringes [24] or similar" methods [25]. 

Ab initio calculations were carried out for all the low-lying non-Rydberg states of the systems N2, 02, NO, Of, and NO+. In N2, for example, there are 102 molecular states that result from nitrogen atoms in the lowest 4S, 2D, and 2P states. These states were all uniformly described using VCI wave functions constructed as described in Section II. Minimum basis, double-f basis and double-f-plus-polarization basis sets were employed for these studies. For the minimum basis-set calculations, which were always carried out first, the VCI wave functions represent full Cl projections with the constraint that the K shells were kept frozen for all states. However, no constraint on the 2og and 2ou orbitals was made since a Cl among these orbitals is necessary to ensure proper description of the hole states in these molecules, such as C3n of N2. The calculations all have the property of asymptotically connecting with the correct atomic states. This computational method has previously been applied, with reliable results, to both closed- and open-shell systems.6 9 11... 

Rydberg atoms, atoms in states of high principal quantum number, n, are atoms with exaggerated properties. While they have only been studied intensely since the nineteen seventies, they have played a role in atomic physics since the beginning of quantitative atomic spectroscopy. Their role in the early days of atomic spectroscopy is described by White.1... 

One of the first properties to be explored was the sensitivity of Rydberg atoms to external electric fields, the Stark effect. While ground state atoms are nearly immune to electric fields, relatively modest electric fields not only perturb the Rydberg energy levels, but even ionize Rydberg atoms, as was shown in early... 

Fig. 2.1 Rydberg atoms of (a) H and (b) Na. In H the electron orbits around the point charge of the proton. In Na it orbits around the +11 nuclear charge and ten inner shell electrons. In high states Na behaves identically to H, but in low states the Na electron penetrates and polarizes the inner shell electrons of the Na+ core.

Fig. 3.2 The fast beam approach of Bayfield and Koch (ref. 13). H+ ions of roughly 10 keV energy pass through a charge exchange cell forming a fast beam of H Rydberg atoms. Down-stream from the charge exchange cell the ions are deflected from the beam and a band of n states is selected by a square wave modulated ionization field.

In Fig. 5.1 we show p(v) vs v at 300 K using both frequency and wavenumber as abscissae. A typical optical transition from the ground state of an atom has frequency v = 3x 1014 Hz, and a transition between two Rydberg states has frequency v 3x 1011 Hz. Thus, it is apparent from Fig. 5.1 that to a ground state atom the black body radiation appears as a slowly varying, nearly static field, whereas to a Rydberg atom it appears to be a rapidly varying field. 

In addition to driving transitions to discrete states the black body radiation can also photoionize the Rydberg atoms. The photoionization rate, l/r f is given by8... 

In this chapter we have implicitly assumed the Rydberg atom to be a one electron-atom. In the perturbed Rydberg series of, for example, alkaline earth atoms, Rydberg states can have mixed valence-Rydberg character. In such states the black body effects are reduced by a factor equal to the fractional Rydberg character.14... 

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