A Viewpoint on : Precise Quantization of the Anomalous Hall Effect near Zero Magnetic Field
A Viewpoint on : Precise Quantization of the Anomalous Hall Effect near Zero Magnetic Field
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发表时间：
2015
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通讯作者：
A. Bestwick;E. Fox;X. Kou;L. Pan;Kang L. Wang;D. Goldhaber-Gordon
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作者：
A. Bestwick;E. Fox;X. Kou;L. Pan;Kang L. Wang;D. Goldhaber-Gordon
量子霍尔效应是在像石墨烯这样的二维电子系统中，在大的外加磁场下观察到的电阻的惊人量子化。在量子霍尔系统中，横向电阻（在样品宽度上测量）具有量化值h/νe2，其中h是普朗克常数，e是基本电荷，ν是整数或分数。霍尔电阻的极高测量精度在计量学中有着重要的应用，提供了当今欧姆的标准定义。该效应的另一个关键特征是纵向电阻（沿沿着样品长度测量）消失：电子可以沿着样品的边缘沿着无耗散地传输。因此，量子霍尔系统可以作为完美的电线，几乎没有能量消耗。
The quantum Hall effect is the striking quantization of resistance observed under a large applied magnetic field in two-dimensional electron systems like graphene. In a quantum Hall system, the transverse resistance (measured across the width of the sample) takes on quantized values h/νe2, where h is Planck’s constant, e the elementary charge, and ν an integer or a fraction. The extreme precision with which the Hall resistance can be measured has important applications in metrology, providing today’s standard definition of the ohm. Another key feature of the effect is that the longitudinal resistance (measured along the length of the sample) vanishes: electrons can be transported without dissipation along the edges of the sample. Quantum Hall systems could thus act as perfect wires with little energy consumption.