We present calculations of the magnetic ground state of Cs2CuCl4 in an applied magnetic field, with the aim of understanding the commensurately ordered state that has been discovered in recent experiments. This layered material is a realization of a Heisenberg antiferromagnet on an anisotropic triangular lattice. Its behavior in a magnetic field depends on field orientation, because of weak Dzy...

Photoelectron spectra of HCO2 2 and DCO2 2 at 299 nm, 266 nm, and 213 nm are reported. Photodetachment accesses the A1 , B2 , and A2 states of the formlyoxyl radical, HCO2. The A1 state is assigned as the HCO2 ground state, although it is nearly degenerate with the B2 state ~T050.027 eV!, and the A2 state lies at T050.536 eV. The electron affinity of HCO2 is 3.49860.015 eV. The spectra show par...

Strong field high harmonic generation (HHG) can reveal the quantum structure of the source molecule. We calculate the effect of interference between the recombining photoelectron and the orbital from which it was field ionized in the single-active-electron standard picture of HHG in N2 and CO2. We compare our results for the highest occupied molecular orbitals (HOMO’s) to the predictions of a p...

Direct optical absorption measurements ofjet-cooled metal clusters formed in a pulsed molecular beam have been made using a sensitive new absorption technique employing pulsed laser sources. Metal clusters and other metal containing species have been observed in this initial study. Absorption measurements of the Cu, ‘A;-‘E’ system reveal strong intensities for vibronic bands seen only weakly in...

At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and b̄c mesons in high energy e+e− and hadronic collisions is dominated by parton fragmentation. We calculate the heavy quark fragmentation functions into the D-wave quarkonium and b̄c mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In...

The energy density in Fulling-Rindler vacuum, which is known to be negative " everywhere " is shown to be positive and singular on the horizons in such a fashion as to guarantee the positivity of the total energy. The mechanism of compensation is displayed in detail. 1 1. Introduction In connection with the problem of the radiation emitted and absorbed by an accelerating observer [1, 2, 3, 10, ...

We investigate theoretically the ground state of the FeMn binary alloy monolayer on the W(001) surface, the stability of different magnetic configurations (ferro/antiferromagnetic, disordered local moments, etc.) and estimate concentrations at which a transition occurs between different magnetic orders. The tight-binding linear muffin-tin orbital method combined with the coherent potential appr...

Isotropic S = 1/2 quasi-one-dimensional antiferromagnets are considered within the bosonization method. The 1/z ⊥-corrections to the interchain mean-field theory (where z ⊥ is the number of nearest neighbors in transverse to chain directions) are obtained for the ground-state sublattice magnetization S 0 and Neel temperature T N. The corrections to T N make up about 25% of mean-field value, whi...

We compute the vibronic spectrum of gas phase fullerene negative ions C60 and C 2− 60 . We treat accurately the linear dynamical Jahn-Teller of these ions in their ground state. In particular, coupling of the t1u orbital to the eight Hg vibrational modes is handled by exact diagonalizations including up to six vibrons. The resulting spectrum is characterized by large splittings, which should be...

Measurements are presented for the density of ground-state neutral xenon atoms in the near field of a 200W co-axial Hall thruster. The diagnostic strategy employed is a variation of a classical absorption technique, using retro-reflected intrinsic line emission from the resonance 147 nm vacuum ultraviolet (VUV) transition in atomic xenon as a source for absorption. In this way the technique has...