Experimental observation of spontaneous chaotic current oscillations in GaAs/Al_(0.45)Ga_(0.55)As superlattices at room temperature

• 来源期刊: 科学通报(英文版)
• 学科: 物理学
• 年，卷（期）: 2012,（17）
• 页码范围: 2070-2072
• 页数: 3页
• 分类号: O471
• 语种: 中文

摘要

Spontaneous self-sustained chaotic current oscillations are observed experimentally in lightly-doped weakly-coupled GaAs/Al0.45Ga0.55As superlattices at room temperature for the first time.The mole fraction of Aluminum in the barrier is chosen to be 0.45 to suppress the thermal carrier leakage through the X-band valley,The effective nonlinearity induced by the sequential well-to-well resonant tunneling can still be strong enough to induce spontaneous chaotic current oscillations even at room temperature,The frequency spectrum of the chaotic current oscillations is ranged from DC to 4 GHz,which can be used as ultra-wide-band noise sources with a bandwidth of several Giga Hertz.