Driven Diatomic Frenkel–Kontorova Model: Resonant Steps, Spatiotemporal Dynamics and Dynamical Phase Diagrams**The project partially supported by National Natural Science Foundation of China (Grant Nos 19775008 and 1945004), and Doctoral Program Foundation of Institution of Higher Education of China

Abstract

The resonant steps, spatiotemporal dynamics and dynamical phase diagrams of the driven diatomic Frenkel–Kontorova model are studied. The complete resonant velocity spectrum which relates only to the winding number is given. The diatomic effects result in each resonant step which is characterized by two integer pairs and . In the high-velocity regime the linear response of to is often punctuated by the subharmonic resonances . There are two kinds of nonlinear response regimes in the high-velocity regime. A new physical interpretation to the mean-field treatment is presented. The commensurate and incommensurate structures show similar dynamical behaviors except that the latter lacks depinning transition below the Aubry transition point. The increase of makes the critical forces increasing, the transitions smoother and the hysteresis thinner.