| Details: |
Strong correlation between electrons in two dimensional electron systems subjected to large magnetic fields at low temperatures produces a topological quantum liquid that is manifested through the phenomenon of fractional quantum Hall effect in which Hall conductivity quantizes at some specific fractional values in the unit of e^2/h. Based on general principles, Laughlin proposed a manybody wavefunction which is an excellent description for the filling factors 1/m (m odd), but it fails to describe states at other filling factors with similar confidence.
In this talk, I will describe, starting from a Laughlin wavefunction, a simple and elegant scheme for constructing manybody wavefunctions for other fractional quantum Hall states as coupled Laughlin condensates present in different Hilbert subspaces spanned by different sets of analytic functions. Surprisingly, these simple form of the wavefunctions are identical with the wavefunctions proposed in composite fermion theory which is based on a key postulate that the electrons form a bound state with even number of quantum vortices, making themselves composite fermions, and these composite fermions qualify to produce integer quantum Hall state. I will further demonstrate that the quasiparticles and the quasiholes of Laughlin state are composite fermions with different number of attached flux, i.e., composite fermions can be created in the form of excitations. |