Discrete sine-Gordon (SG) chains are studied with path-integral moleculardynamics. Chains commensurate with the substrate show the transition fromcollective quantum creep to pinning at bead masses slightly larger than thosepredicted from the continuous SG model. Within the creep regime, a field-driventransition from creep to complete depinning is identified. The effects ofdisorder in the external potential on the chain's dynamics depend on thepotential's roughness exponent $H$, i.e., quantum and classical fluctuationsaffect the current self-correlation functions differently for $H = 1/2$.
展开▼
机译：离散正弦-戈登（SG）链研究与路径积分的分子动力学。与基体相对应的链显示出从集体量子蠕变到钉扎的过渡，其磁珠质量比连续SG模型所预测的稍大。在蠕变状态内，确定了从蠕变到完全脱钉的场驱动过渡。外部势能紊乱对链动力学的影响取决于势能的粗糙度指数$ H $，即量子波动和经典波动对$ H = 1/2 $的电流自相关函数的影响不同。
展开▼
