Resistively Detected NMR in GaAs/AlGaAs
Resistively Detected NMR in GaAs/AlGaAs
复制标题
GaAs/AlGaAs 中的电阻检测 NMR
DOI：
10.1007/978-3-540-79365-6_3
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
G. Gervais
中科院分区：
文献类型：
--
作者：
G. Gervais
自20世纪40年代末发展以来，核磁共振（NMR）已成为探测液体和固体物质局部场分布以及提供自旋和涡旋动力学重要信息的有力技术。虽然在核磁共振波谱方面取得了重大进展，但传统的感应探测核磁共振仍然是一项技术，很难缩小到非常小的尺寸系统。在大多数情况下，核磁共振仍然局限于样品中存在的核自旋总数超过~ 1016的系统，因此禁止在各种系统中进行核磁共振检测。中、纳米尺度材料的工程、设计和制造的最新进展导致了传统核磁共振技术由于“自旋太少”问题而无法利用的实验测量差距。例如，宽约30 nm的GaAs/AlGaAs半导体异质结构界面的核自旋小于1015个，量子点自旋为106 - 1010个，单个碳纳米管自旋为103个。这些系统中可用的原子核很少，这使得传统的核磁共振测量非常困难，如果不是完全不可能的话，除非核磁共振检测方案可以以一种全新的方式重新定义。传统的电感式核磁共振存在一种有吸引力的替代方案，它可以通过电阻检测获得gaas基半导体中原子核的观点。这种方法似乎有望解决更广泛的小尺寸系统问题，如介观量子点和其他纳米结构。在此，我们将回顾电阻探测核磁共振领域的最新进展，并讨论诸如弛豫时间实验和脉冲技术的发展等最新进展。最后，我们讨论了如何将电阻检测到的核磁共振推到底部，以获得具有“非常少自旋”的纳米尺度的完整原子核观点。
Since its development in the late 1940s, nuclear magnetic resonance (NMR) has emerged as a powerful technique for probing the local field distribution in liquid and solid matter as well as providing important information on spin and vortex dynamics. While significant progress has been achieved in NMR spectroscopy, conventionalinductively detectedNMR remains essentially abulktechnique that proves to be extremely difficult to scale down to systems of very small sizes. For the most part, NMR remains limited to systems with a total number of nuclear spins present in the sample exceeding ∼1016, hence prohibiting the NMR detection in a wide variety of systems. Recent advances in the engineering, design and fabrication of meso- and nanoscaled materials have resulted in an experimental measurement gap where conventional NMR techniques cannot be utilized because of the “too few spins” problem. For example, a GaAs/AlGaAs semiconductor heterostructure interface ∼30 nm wide has less than 1015nuclear spins, a quantum dot ∼106–1010spins and a single carbon nanotube 103spins. The very few nuclei available in these systems makes traditional NMR measurements extremely difficult, if not totally impossible, unless the NMR detection scheme could be redefined in an entirely new way.One appealing alternative to the conventional inductive NMR exists and makes it possible to obtain the nucleus’ point-of-view in GaAs-based semiconductors through a resistive detection. This approach seems promising to tackle a broader class of problems in systems of small sizes such as mesoscopic quantum dots and other nanostructures. We shall review here the state-of-the-art in the field of resistively detected NMR, and discuss recent advances such as the relaxation-time experiments and the development of pulsed techniques. Finally, we discuss how resistively detected NMR might be pushed towards the bottom so as to obtain a complete nucleus’ point-of-view of the nanoscale with “very little spins”.
影响因子：
8.6
作者：
K. Ono;S. Tarucha
通讯作者：
K. Ono;S. Tarucha