共查询到19条相似文献,搜索用时 109 毫秒
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在霍尔元件测磁场的实验过程中,由于霍尔元件无保护电路,在线路接错和操作不正常的情况下,经常造成大电流损坏霍尔元件,严重影响正常的教学工作.我们在实践中经过电路改进,增加保护电路后,有效地防止了这种故障的发生.1工作原理 霍尔元件I 端在正常工作情况下,流过I端的电流绝对值小于6mA,R1取值为330 ,其两端压降小于 2V,经 D1或 D2, W1至 Th1的门极 G,此电压达不到 Th1门极的导通电压 ugTh1不导通,流过Th1主端子T1-T2的电流为零,所以加入保护电路后对测量结果无影响.当线路不正… 相似文献
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用霍尔元件测微小位移 总被引:4,自引:0,他引:4
利用霍尔元件的磁电阻效应与磁感应强度的平方成正比这一关系,通过改变磁铁与霍尔元件的距离引起霍尔元件的电阻改变,再把这一电阻信号转换为电压信号,测量电压信号从而得到与之对应的位移量。 相似文献
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大学物理实验中,“用霍尔效应法测量磁场”实验是工科各专业必做的实验之一,由于学生因接错线路而导致霍尔元件被烧毁.一个学期下来总得有六七台甚至更多.为改进这个实验装置,通过研究,如果在霍尔元件电流输入端和电压输出端各串联一个额定电流为32mA的保险丝就能达到这个目的. 相似文献
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1引言
大学物理实验中,“用霍尔效应法测量磁场”实验是工科各专业必做的实验之一,笔者已给学生上这个实验许多年,深感这个实验装置必须改进;因为在实验中,虽然笔者再三强调不要把励磁电流接至霍尔元件上,仍然有部分学生因接错线路而导致霍尔元件被烧毁.由于上大学物理实验课的学生多,仪器的使用率特别高,所以一个学期下来总有六七台甚至更多台霍尔效应实验仪中的霍尔元件被烧毁而需更换. 相似文献
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本首先对霍尔效应测量中的系统误差作了叙述,对系统误差中的热能流引起的不等位电势提出了自己的见解,并对结果进行了评述。 相似文献
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Current breakdown of the integer and fractional quantum Hall effects detected by torque magnetometry
A. J. Matthews J. P. Watts M. Zhu A. Usher M. Elliott W. G. Herrenden-Harker P. R. Morris M. Y. Simmons D. A. Ritchie 《Physica E: Low-dimensional Systems and Nanostructures》2000,6(1-4)
We have developed a novel technique that enables measurements of the breakdown of both the integer and fractional quantum Hall effects in a two-dimensional electron system without the need to contact the sample. The critical Hall electric fields that we measure are significantly higher than those reported by other workers, and support the quasi-elastic inter-Landau-level tunnelling model of breakdown. Comparison of the fractional quantum Hall effect results with those obtained on the integer quantum Hall effect allows the fractional quantum Hall effect energy gap to be determined and provides a test of the composite-fermion theory. The temperature dependence of the critical current gives an insight into the mechanism by which momentum may be conserved during the breakdown process. 相似文献
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Ady Stern 《Annals of Physics》2008,323(1):204-249
The dichotomy between fermions and bosons is at the root of many physical phenomena, from metallic conduction of electricity to super-fluidity, and from the periodic table to coherent propagation of light. The dichotomy originates from the symmetry of the quantum mechanical wave function to the interchange of two identical particles. In systems that are confined to two spatial dimensions particles that are neither fermions nor bosons, coined “anyons”, may exist. The fractional quantum Hall effect offers an experimental system where this possibility is realized. In this paper we present the concept of anyons, we explain why the observation of the fractional quantum Hall effect almost forces the notion of anyons upon us, and we review several possible ways for a direct observation of the physics of anyons. Furthermore, we devote a large part of the paper to non-abelian anyons, motivating their existence from the point of view of trial wave functions, giving a simple exposition of their relation to conformal field theories, and reviewing several proposals for their direct observation. 相似文献
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We report on a proof-of-concept study of split-cell magnetic storage in which multi-bit magnetic memory cells are composed of several multilevel ferromagnetic dots with perpendicular magnetic anisotropy. Extraordinary Hall effect is used for reading the data. Feasibility of the approach is supported by realization of four-, eight- and sixteen- state cells. 相似文献
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采用微机控制和数字式数据采集系统,在变温环境下(77~420 K)对长为6.0 mm、宽为4.0 mm、厚为0.6 mm的锗样品薄片进行霍尔效应相关数据测量;通过对测量的霍尔电压作数据处理得到锗的霍尔系数RH(T)、电导率σ(T)和霍尔迁移率μH(T)与温度的依赖关系.该实验结果对学生理解半导体物理中的相关知识有重要意义. 相似文献