v 1 3 J un 1 99 3 Vibrations and Berry Phases of Charged
نویسنده
چکیده
A simple model of electron-vibron interactions in buckminster-fullerene ions is solved semiclassically. Electronic degeneracies of C 60 n− induce dynamical Jahn-Teller distortions, which are unimodal for n = 3 and bimodal for n = 3. The quantization of motion along the Jahn-Teller manifold leads to a symmetric-top rotator Hamiltonian. I find Molecular Aharonov-Bohm effects where electronic Berry phases determine the vibrational spectra, zero point fluctuations, and electrons' pair binding energies. The latter are relevant to superconductivity in alkali-fullerenes. For polyatomic molecules, the adiabatic approximation is often used to eliminate fast electrons in favor of an effective potential for the slow nuclei. This approximation requires special care when the positions of the nuclear coordinates are near points of electronic degeneracy. If the electron-ion interaction is linear in the ionic displacements (a generic case for symmetric, non colinear molecules [1]) the classical Jahn Teller theory [2] predicts that the molecule distorts and some (or all) of the electronic degeneracy is lifted. The *
منابع مشابه
ua nt - p h / 99 05 10 1 v 1 3 1 M ay 1 99 9 Geometric phases for generalised squeezed coherent states
A simple technique is used to obtain a general formula for the Berry phase (and the corresponding Hannay angle) for an arbitrary Hamiltonian with an equally-spaced spectrum and appropriate ladder operators connecting the eigenstates. The formalism is first applied to a general deformation of the oscillator involving both squeezing and displacement. Earlier results are shown to emerge as special...
متن کاملD ec 1 99 2 Spin Tunneling , Berry phases and Doped Antiferromagnets
Interference effects between Berry phase factors in spin tunneling systems have been discussed in recent Letters by Loss, DiVincenzo and Grinstein (LDG) [1] and von Delft and Henley (vDH) [2]. As physical realizations, LDG proposed tunneling of magnetic clusters, and vDH proposed an anisotropic spin hamiltonian and the Heisenberg antiferromagnet on the Kagomé lattice. In these examples, for cer...
متن کاملar X iv : a st ro - p h / 99 04 24 4 v 2 3 J un 1 99 9 Is SGR 1900 + 14 a Magnetar ?
We present RXTE observations of the soft gamma–ray repeater SGR
متن کامل