Hall effect was discovered by physicist Hall in 1879, which defined the relationship between magnetic field and induced voltage. This effect is completely different from traditional electromagnetic induction. When the current passes through the conductor in the magnetic field, the magnetic field will generate a force perpendicular to the direction of electron movement, thus generating a potential difference in two directions perpendicular to the conductor and the magnetic induction line.
Although this effect has been known and understood for many years, the sensor based on Hall effect has not been put into practical use until the material technology has made great progress, until there are high-strength permanent magnets and signal conditioning circuits working at small voltage output. According to different designs and configurations, Hall effect sensors can be used as on/off sensors or linear sensors, which are widely used in power systems.
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The development of Hall effect;
About 100 years after the discovery of the Hall effect, German physicist Klitsyn and others discovered the quantum Hall effect when studying semiconductors at extremely low temperature and strong magnetic field, which is one of the amazing advances in condensed matter physics, and Klitsyn won the Nobel Prize in physics for it. ?
Later, Chinese-American physicist Cui Qi and American physicists laughlin and Stormer discovered the fractional quantum Hall effect when studying the quantum Hall effect in a stronger magnetic field. This discovery gave people a better understanding of quantum phenomena, and they won the 1998 Nobel Prize in Physics.
Now, Zhang Shousheng, an alumnus of Fudan University and a professor at Stanford University, is working with his alma mater to study the quantum spin Hall effect. The "quantum spin Hall effect" was first predicted by Professor Zhang Shousheng and later confirmed by experiments. This achievement is one of the top ten scientific advances in 2007 selected by American Science magazine.
If this effect is effective at room temperature, it may lead to the emergence of new low-power "spintronics" computing devices. Many high-precision voltage and current sensors used in industry are made according to Hall effect, and the error accuracy can reach below 0. 1%.
Led by Tsinghua University academician Xue Qikun, a team of researchers from Tsinghua University, Institute of Physics of Chinese Academy of Sciences and Stanford University has made a major breakthrough in the study of quantum anomalous Hall effect. They observed the quantum anomalous Hall effect for the first time in the experiment, which is an important physical phenomenon independently observed by Chinese scientists and an important scientific discovery in basic research in the field of physics.