在近魔法角度扭曲双层石墨烯中低频电阻噪声
Pritam Pal1, Saisab Bhowmik2, Aparna Parappurath1
1Department of Physics, Indian Institute of Science, Bangalore 560012, India.
ACS nano
|January 17, 2025
概括
在扭曲双层石墨烯 (tBLG) 中的噪声测量揭示了在高温和低温下不同的行为. 在高温下,观察到1/f噪声,而在低温下显示一个随机的电报信号,突出显示了对电子相和相互作用的敏感性.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 量子电子学 量子电子学
背景情况:
- 低频电阻波动 (噪声) 对设备性能和探测电子性能至关重要.
- 在魔法角度附近的扭曲双层石墨烯 (tBLG) 由于强烈的相关性而表现出复杂的电子相.
- 了解tBLG中的噪声机制是利用其独特电子行为的关键.
研究的目的:
- 为了调查tBLG在魔力角度附近的电噪声的特征和起源.
- 在tBLG中将噪声信号与电子相和相互作用效应相关联.
- 与传统运输方法相比,评估噪声测量的灵敏度.
主要方法:
- 在tBLG样本上进行了电阻噪声测量,测量距离魔法角 (θ ∼ 1°) 附近.
- 噪声测量在各种温度范围内进行,从高 (60-70 K) 到低 (10 K).
- 使用功率光谱密度 (PSD) 分析来描述噪声的频率依赖性.
主要成果:
- 在高温下,噪声遵循1/f功率光谱密度,与麦克沃特模型相一致.
- 在低温下,观察到具有1/f^2类PSD的双级随机电报信号 (RTS),归因于hBN缺陷共振.
- 莫雷波段内的低温噪声在特定填充处呈现最小值,与范霍夫奇点和强大的库伦相互作用相关.
结论:
- 在tBLG中的噪声表现出明显的温度依赖的行为,为不同的散射和相互作用机制提供了洞察力.
- 观察到的低温RTS与封装hBN层的相互作用有关.
- 噪声测量对tBLG中的相互作用效应比传统的时间平均运输测量更敏感.
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