Upstream neutral modes in the fractional Quantum Hall regime

Speaker
Yaron Gross, Weizmann Institute
Date
06/06/2013 - 15:15Add to Calendar 2013-06-06 15:15:00 2013-06-06 15:15:00 Upstream neutral modes in the fractional Quantum Hall regime   Counter propagating (upstream) chiral neutral edge modes, which were predicted to be present in hole-conjugate states, were observed recently in a variety of fractional Quantum Hall States, by measuring charge noise that resulted after partitioning the neutral mode by a constriction. The observation of such modes raised new questions regarding their microscopical nature and the interplay between the charge and neutral edge modes.  Moreover, it opened a new way to probe the wave function of the fractional Quantum Hall states at the first excited Landau level, where some states are predicted to be of non-abelian nature.   In this talk, I will present this emerging new field. First I will focus on measurements performed at the ubiquitous n=2/3, establishing our measurement techniques and revealing new details on the properties of the neutral modes.  Secondly, I will present detailed investigation of the neutral modes at the first excited Landau level, demonstrating the existence of an upstream neutral mode in the n=8/3 and n=5/2 states and excluding its existence at the n=7/3 state.  These results supports the non-abelian, anti-pfaffian to be the n=5/2 wave function. Resnick Building (209), seminar room 210 המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Resnick Building (209), seminar room 210
Abstract

 

Counter propagating (upstream) chiral neutral edge modes, which were predicted to be present in hole-conjugate states, were observed recently in a variety of fractional Quantum Hall States, by measuring charge noise that resulted after partitioning the neutral mode by a constriction. The observation of such modes raised new questions regarding their microscopical nature and the interplay between the charge and neutral edge modes.  Moreover, it opened a new way to probe the wave function of the fractional Quantum Hall states at the first excited Landau level, where some states are predicted to be of non-abelian nature.

 

In this talk, I will present this emerging new field. First I will focus on measurements performed at the ubiquitous n=2/3, establishing our measurement techniques and revealing new details on the properties of the neutral modes.  Secondly, I will present detailed investigation of the neutral modes at the first excited Landau level, demonstrating the existence of an upstream neutral mode in the n=8/3 and n=5/2 states and excluding its existence at the n=7/3 state.  These results supports the non-abelian, anti-pfaffian to be the n=5/2 wave function.

תאריך עדכון אחרון : 02/04/2013