Noise-Induced Current Switching in Semiconductor Superlattices: Observation of Nonexponential Kinetics in a High-Dimensional System

作者：Bomze Yu^*; Hey R; Grahn H T; Teitsworth S W

来源：Physical Review Letters, 2012, 109(2): 026801.

DOI：10.1103/PhysRevLett.109.026801

We report on measurements of first-passage-time distributions associated with current switching in weakly coupled GaAs/A1As superlattices driven by shot noise, a system that is both far from equilibrium and high dimensional. Static current-voltage (I-V) characteristics exhibit multiple current branches and bistability; precision, high-bandwidth current switching data are collected in response to steps in the applied voltage to final voltages V-1 near the end of a current branch. For a range of V-1 values, the measured switching times vary stochastically. At short times (less than or similar to 10 mu s), the switching time distributions decay exponentially, while at longer times the distributions develop nonexponential tails that follow an approximate power law over several decades. The power law decay behavior is attributed to the presence of multiple switching pathways, which may arise from small spatial variations in the superlattice growth parameters.

• 出版日期2012-7-9