חדשות ואירועים

Electron Interference, Noise, and Interactions in Edge States in the Quantum Hall Effect

20.3.12, 14:00
Room 426/8

Recently there is a burst of interest in measurements of interference patterns and noise of topologically-protected edge states in the quantum Hall effect regime. One reason for this interest is the potential of these experiments in demonstrating fractional and non-Abelian statistics between particles, which may lead to a realization of quantum computation. Another reason is that a new and diverse group of experiments revealed a non-trivial influence of the Coulomb interaction between electrons on the interference patterns and on the noise, which we only now begin to understand. In the talk, I will give an overview of various experiments done in this research field and the connections between them, and I will outline the theories which we developed in order to explain their resultsThe fractional quantum Hall effect arises because of the collective behavior of the electrons confined in a two-dimensional system. The electrons behave as if they are a composite particle composed of an electron and three magnetic-flux quanta. The tell-tale signature of this behavior is that the Hall resistance of the material — the transverse electrical resistance in the two-dimensional plane — jumps in discrete steps as the field is increased. These steps appear at values equal to the "von Klitzing" constant divided by either an integer or a fraction