Electronically driven phase transitions in a quasi-one-dimensional adsorbate system

Random registry shifts in quasi-one-dimensional adsorbate systems

J. Schäfer, S. C. Erwin, M. Hansmann, Z. Song, E. Rotenberg, S. D. Kevan, C. S. Hellberg, and K. Horn Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 Center for Computational Materials Science, Naval Research Laboratory, Washington DC 20375 Fritz-Haber-Institut der Max-Planck-Gesellschaft...

Fluctuations and phase separation in a quasi-one-dimensional system.

Phase transitions in a quasi-one-dimensional surface system on a metal substrate are investigated as a function of temperature. Upon cooling the system shows a loss of long-range order, fluctuations, and a transition into an inhomogeneous ground state due to competition of local adsorbate-adsorbate interactions with an incommensurate charge density wave. This agrees with a general phase diagram...

Electronically driven adsorbate excitation mechanism in femtosecond-pulse laser desorption.

One-dimensional phase transitions in a two-dimensional optical lattice

A phase transition for bosonic atoms in a two-dimensional anisotropic optical lattice is considered. If the tunnelling rates in two directions are different, the system can undergo a transition between a two-dimensional superfluid and a one-dimensional Mott insulating array of strongly coupled tubes. The connection to other lattice models is exploited in order to better understand the phase tra...

Field-driven phase transitions in a quasi-two-dimensional quantum antiferromagnet

We report magnetic susceptibility, specific heat, and neutron scattering measurements as a function of applied magnetic field and temperature to characterize the S = 1/2 quasi-two-dimensional frustrated magnet piperazinium hexachlorodicuprate (PHCC). The experiments reveal four distinct phases. At low temperatures and fields the material forms a quantum paramagnet with a 1 meV singlet triplet g...