MAGNETIC-FIELD-DRIVEN DESTRUCTION OF QUANTUM HALL STATES IN A DOUBLE QUANTUM-WELL

The magnetotransport of double-quantum-well structures reveals a high-magnetic-field regime in which quantum Hall states at odd-integer are missing, where is the number of filled energy levels. In these double wells, the =odd quantum Hall states originate from the symmetric-antisymmetric energy gap. With increasing barrier thickness between the two wells, initially the magnetic field destroys only the =1 state, then both the =1 and =3 states disappear. We attribute their destruction to the onset of interwell electron density fluctuations. © 1990 The American Physical Society.