### Speaker

Dam Thanh Son

### Description

The theory of the fractional quantum Hall effect is based on the notion of the composite fermion, which is the low-energy quasiparticle for filling factor close to 1/2. I will show that the particle-hole symmetry of the half-filled Landau level implies that the composite fermion is a Dirac particle, characterized by a Berry phase of $pi$ around the Fermi surface. Physical consequences are discussed.