在零磁场时,三层石墨烯中的非线性Nernst效应
Hao Liu1, Jingru Li1, Zhifan Zhang2
1State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai, China.
Nature nanotechnology
|June 23, 2025
概括
研究人员在没有磁场的三层石墨烯中观察到非线性Nernst效应 (NNE). 这一发现为热电能采集和冷却技术开辟了新的途径.
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
- 热电学是一种热电学.
背景情况:
- 纳恩斯特效应从温度梯度中产生横向电压,这对于热电能转换至关重要.
- 由于时间逆向对称性,在非磁性材料中禁止使用线性纳斯特效应,但允许使用非线性效应.
研究的目的:
- 在非磁性ABA三层石墨烯中实验观察和描述非线性Nernst效应 (NNE).
- 调查NNE在先进热电应用中的潜力.
主要方法:
- 使用电测量的NNE的实验观测.
- 在低温温度 (<12 K) 应用交替温度梯度.
- 分析NNE对温度梯度和接近电荷中立点的依赖性.
主要成果:
- 在没有外部磁场的情况下,在ABA三层石墨烯中成功检测了NNE.
- NNE显示了对温度梯度的二次依赖.
- 在2K测量时,测出了高达300μV K-1的巨大有效纳斯特系数,超过了磁性材料中的线性系数.
- 建立了NNE和线性西贝克效应之间的缩放定律,表明斜散射是占主导地位的机制.
结论:
- 该研究证明了在非磁性材料中观察和利用NNE的可行性.
- 结果表明,NNE是新型热电能收集和冷却设备的有希望的机制.
- 这项研究为开发先进的热电技术提供了新的途径.
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