Imaging of nonlocal hot-electron energy dissipation via shot noise
Imaging of nonlocal hot-electron energy dissipation via shot noise
复制标题
通过散粒噪声对非局域热电子能量耗散进行成像
DOI：
10.1126/science.aam9991
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发表时间：
2018-05-18
期刊：
影响因子：
56.9
通讯作者：
Lu, Wei
中科院分区：
文献类型：
--
作者：
Weng, Qianchun;Komiyama, Susumu;Lu, Wei
在现代微电子器件中，热电子在纳米尺度上加速、散射和耗散能量。尽管最近在纳米测温技术的进展，热电子能量耗散的直接实空间映射是具有挑战性的，因为现有的技术仅限于探测晶格，而不是电子。我们通过测量与超快热电子动力学过程（类似于21太赫兹）相关的局部电流波动或散粒噪声来实现电子纳米测温。利用扫描和无接触的钨尖作为本地噪声探针，我们直接可视化热电子分布之前，与主机砷化镓/砷化镓铝晶格的热平衡。与nanoconstriction设备，我们揭示了意想不到的非局部能量耗散在室温下，这是让人想起低温量子导体的弹道输运。
In modern microelectronic devices, hot electrons accelerate, scatter, and dissipate energy in nanoscale dimensions. Despite recent progress in nanothermometry, direct real-space mapping of hot-electron energy dissipation is challenging because existing techniques are restricted to probing the lattice rather than the electrons. We realize electronic nanothermometry by measuring local current fluctuations, or shot noise, associated with ultrafast hot-electron kinetic processes (similar to 21 terahertz). Exploiting a scanning and contact-free tungsten tip as a local noise probe, we directly visualize hot-electron distributions before their thermal equilibration with the host gallium arsenide/aluminium gallium arsenide crystal lattice. With nanoconstriction devices, we reveal unexpected nonlocal energy dissipation at room temperature, which is reminiscent of ballistic transport of low-temperature quantum conductors.