双带紧束缚模型中噪声对超晶格中电子输运性质的影响(英文)

Effect of External Noise on the Transport Propertyof Two-band Tight-binding Superlattices

运用直交流电场驱动下的双带紧束缚模型,研究了噪声对超晶格中电子输运性质的影响.数值结果表明,外部噪声能够破坏瞬时电流的周期性并且能够削减长时平均电流的峰值.随着噪声强度的增加,平均电流峰的高度降低,宽度增加;当增大噪声的衰减常数时,平均电流峰会有类似上述变化.

Within a two-band tight-binding model driven by a dc-ac electric field, we investigate the effect of external noise on the transport property of electrons in superlattices. We find that external noise can destroy the periodicity of the transient current and cancel the long-time average current peaks. The magnitude of the noise is usually in the order of ten percent of E0 （ static electric field）,which affects the transient and averaged currents strongly. Increasing the noise strength, the height of the current peaks decreases, and the width increases. A similar change appears while we increase the decay constant of the noise.