Dynamical mode locking phenomena in incommensurate structures of the dc- and ac-driven overdamped FrenkelKontorova model are studied by molecular-dynamics simulations.It is found that the Shapiro steps exhibit signifi...Dynamical mode locking phenomena in incommensurate structures of the dc- and ac-driven overdamped FrenkelKontorova model are studied by molecular-dynamics simulations.It is found that the Shapiro steps exhibit significantly different amplitude and frequency dependences from the ones observed in the commensurate structures.The step widths still oscillate with the amplitude,but the form is no longer Bessel-like,i.e.,the anomaly appears in our simulations.The same type of anomalies is also exhibited by the critical depinning force.The oscillatory behavior and the anomalies are also revealed in the ((F),Fac) phase diagram where three phases are observed.These oscillations are directly correlated with the existence and the stability of interference phenomena in real systems.展开更多
The mode-locking phenomena in the dc-and ac-driven overdamped two-dimensional Frenkel-Kontorowa modelwith triangular symmetric structures are studied.'The obtained results show that the transvarse velocity(μz)inc...The mode-locking phenomena in the dc-and ac-driven overdamped two-dimensional Frenkel-Kontorowa modelwith triangular symmetric structures are studied.'The obtained results show that the transvarse velocity(μz)increasas in a series of quantized steps nyua(n=0,1,2,3…).Moreover,the positive or negative rectification oflongitudinal velocity(μy)can occur when n is an odd number.It is also found in our simulations that the criticaldepinning force ascillates with the amplitude of ac-driven force,i.e.,the systemn is dominated by the ac-drivenforce.The oscillatory behavior is strongly determined by the initial phase of ac force.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 91026005 and 11105054the Foundation for Distinguished Young Talents in Higher Education of Guangdong Province under Grant No LYM10065the Domestic Visiting Scholars Program of the Doctoral Candidates of Northwest Normal University of China.
文摘Dynamical mode locking phenomena in incommensurate structures of the dc- and ac-driven overdamped FrenkelKontorova model are studied by molecular-dynamics simulations.It is found that the Shapiro steps exhibit significantly different amplitude and frequency dependences from the ones observed in the commensurate structures.The step widths still oscillate with the amplitude,but the form is no longer Bessel-like,i.e.,the anomaly appears in our simulations.The same type of anomalies is also exhibited by the critical depinning force.The oscillatory behavior and the anomalies are also revealed in the ((F),Fac) phase diagram where three phases are observed.These oscillations are directly correlated with the existence and the stability of interference phenomena in real systems.
文摘The mode-locking phenomena in the dc-and ac-driven overdamped two-dimensional Frenkel-Kontorowa modelwith triangular symmetric structures are studied.'The obtained results show that the transvarse velocity(μz)increasas in a series of quantized steps nyua(n=0,1,2,3…).Moreover,the positive or negative rectification oflongitudinal velocity(μy)can occur when n is an odd number.It is also found in our simulations that the criticaldepinning force ascillates with the amplitude of ac-driven force,i.e.,the systemn is dominated by the ac-drivenforce.The oscillatory behavior is strongly determined by the initial phase of ac force.
