Yiming Qiu
Department of Physics and Astronomy
Johns Hopkins University
The discovery of Quantum Hall Effect(QHE) is a remarkable achievement in condensed matter physics. At low temperatures and in strong magnetic fields, it is found that the Hall resistance of a two dimensional electron system has plateaus as a function of the number of electrons. In integer quantum Hall effect(IQHE), the Hall resistance at the plateaus turns out to be 
, where i is an integer. In fractional quantum Hall effect(FQHE), i can be a fractional number. Due to the high precision of the measurement, the quantization of the Hall resistance is now used as the standard of resistance. In this paper I try to cover the main aspects of this field. This webpage is a requirement of the first year graduate seminar in the Department of Physics and Astronomy of the Johns Hopkins University.