Effects of lattice geometry and interaction range on polaron dynamics.pdf

Effects of lattice geometry and interaction range on polaron dynamics J.P. Hague,1 P.E. Kornilovitch,2 A.S. Alexandrov,1 and J.H. Samson1 1Department of Physics, Loughborough University, Loughborough, LE11 3TU, United Kingdom 2Hewlett-Packard Company, 1000 NE Circle Blvd, Corvallis, Oregon 97330, USA We study the effects of lattice type on polaron dynamics using a continuous-time quantum Monte- 5 Carlo approach. Holstein and screened Fr¨ohlich polarons are simulated on a number of different 0 Bravais lattices. The effective mass, isotope coefficients, ground state energy and energy spectra, 0 phonon numbers, and density of states are calculated. In addition, the results are compared with 2 weak and strong coupling perturbation theory. For the Holstein polaron, it is found that the v crossover between weak and strong coupling results becomes sharper as the coordination number o is increased. In higher dimensions, polarons are much less mobile at strong coupling, with more N phonons contributing to the polaron. The total energy decreases monotonically with coupling. Spectral properties of the polaron depend on the lattice type considered, with the dimensionality 8 contributing to the shape and the coordination number to the bandwidth. As the range of the 2 electron-phonon interaction is increased, the coordination number becomes less important, with the dimensionality taking the leading role. ] l e PACS numbers: