Dynamics of lattice vibrations for one-dimensional commensurate and incommensurate composites with harmonic interaction

The Commensurate Incommensurate Transition

In condensed matter physics there are many successful models of phase transitions between a more ordered and less ordered state. Break a continuous symmetry and you’ve got yourself a cpmtomipus phase transition. Roughly speaking the transition occurs when the symmetry breaking potential term becomes the dominant one in the free energy and the system ‘contracts’ in phase space decreasing entropy...

Commensurate supersolid of three-dimensional lattice bosons.

Using an unbiased quantum Monte Carlo method, we obtain convincing evidence of the existence of a checkerboard supersolid at a commensurate filling factor 1/2 (a commensurate supersolid) in the soft-core Bose-Hubbard model with nearest-neighbor repulsions on a cubic lattice. In conventional cases, supersolids are realized at incommensurate filling factors by a doped-defect-condensation mechanis...

Data Mining for New Two- and One-Dimensional Weakly Bonded Solids and Lattice-Commensurate Heterostructures.

Layered materials held together by weak interactions including van der Waals forces, such as graphite, have attracted interest for both technological applications and fundamental physics in their layered form and as an isolated single-layer. Only a few dozen single-layer van der Waals solids have been subject to considerable research focus, although there are likely to be many more that could h...

Incommensurate Structure with No Average Lattice : an Example of One Dimensional Quasi-crystal

Incommensurate structure with no average lattice : an example of a one-dimensional quasicrystal

We study the ground state of a simple one-dimensional model describing an incommensurate modulation of the vacancy density of a periodic lattice. We show that this structure, though its Fourier spectrum is always discrete, cannot be interpreted as an average crystal with a superimposed periodic displacive distortion except for a discrete sequence of particular values of the vacancy density. The...