Fractional quantum Hall effect in a parabolic quantum well in tilted magnetic fields

The quasiparticle-quasihole energy gap is studied for a parabolically confined quasi-two-dimensional electron system subjected to a tilted magnetic field. The energy gap is obtained using finite system calculations in a periodic rectangular geometry, and the single-particle mode coupling due to tilting of the magnetic field and the level mixing due to the interparticle Coulomb interaction are taken into account. Spin-polarized electron systems are considered and it is found that adding the magnetic field, parallel to the quasi-two-dimensional electron system, decreases the quasiparticle-quasihole energy gap and compresses the electron system to be thinner. Our results indicate that it is possible to observe a collapse of the fractional quantum Hall effect in a wide parabolic quantum well by tilting the magnetic field.