Multiphonon excitations in boson quantum films

Quantum Sticking, Scattering, and Transmission ofH4eatoms from SuperfluidHCampbell1, Krotscheck2, Saarela3 1998Phys. Rev. Lett.Self Cite261120View full textAdd to dashboardCite

“…The theoretical method used here has been successfully applied to the bulk [15,16], to adsorbed films [17,18] and to droplets [19]; in the latter two it was successful in making detailed and correct predictions about surface states (ripplons and third sound) which also play a very important role in the slab geometry. The theory is adapted here to the slab geometry, including scattering states.…”

“…This is in qualitative agreement with the conclusions of Edwards and collaborators [1][2][3][4] in their results for the related helium atom scattering from the free surface of bulk helium. Our results not only provide insight into the transmission and sticking of a helium beam that was not previously available from theory or experiment, it also provides detailed predictions for the anticipated experiments on slabs.The theoretical method used here has been successfully applied to the bulk [15,16], to adsorbed films [17,18] and to droplets [19]; in the latter two it was successful in making detailed and correct predictions about surface states (ripplons and third sound) which also play a very important role in the slab geometry. The theory is adapted here to the slab geometry, including scattering states.…”

“…2). Including f 2 is sufficient to correct most of the residual disagreement with experiment [15,16,18].…”

“…It is well-known from the theory of the phonon-roton spectrum of bulk liquid 4 He that these low excited states are quantitatively accounted for by a wavefunction of this type containing one-and two-body terms in F λ [15][16][17][18]:…”

Parallel Program Debugging with MAD — A Practical Approach

“…where the matrix elements V mn (p, q, z) are known ground state quantities and the denominator displays the dispersion relations of so-called Feynman excitation [3]. In determining Σ, parallelization is done by data-decomposition along indices m, n and summing up all contributions at the end of the calculation.…”