Zig-zag version of the Frenkel-Kontorova model

Zig-zag version of the Frenkel-Kontorova model.

Quantum Frenkel-Kontorova Model

This paper gives a review of our recent work on the quantum Frenkel-Kontorova model. Using the squeezed state theory and the quantum Monte Carlo method, we have studied the effects of quantum fluctuations on the Aubry transition and the behavior of the ground state wave function. We found that quantum fluctuations renormalize the sinusoidal standard map to a sawtooth map. Although quantum fluct...

The zig-zag product

The expander constructions based on algebraic methods can give expanders that are both explicit (i.e. we can quickly construct the graph, or even obtain neighborhood information without constructing the entire graph, and Ramanujan, meaning that the spectral gap is essentially as large as possible. It also follows from this spectral bound that the edge expansion of Ramanujan graphs is essentiall...

Sliding Friction in the Frenkel-Kontorova Model

A two-dimensional Frenkel-Kontorova model under a steady external force is used to study the nonlinear sliding friction between flat macroscopic surfaces with a lubricant layer in between. The nonequilibrium properties of the model are simulated by a Brownian molecular dynamics and results are obtained as a function of temperature and a microscopic friction parameter η.

Electronic properties of the 1D Frenkel-Kontorova model.

The energy spectra and quantum diffusion of an electron in a 1D incommensurate Frenkel-Kontorova model are studied numerically. We found that the spectral and dynamical properties of an electron display quite different behaviors in the invariance circle regime and in the Cantorus regime. In the former case, it is similar to that of the Harper model, whereas in the latter case, it is similar to ...