Spectroscopic evidence of extended states in the quantized Hall phase of weakly coupled GaAs/AlGaAs multilayers

The influence of interlayer coupling on the formation of the quantized Hall phase at the filling factor nu=2 was studied in multilayer GaAs/AlGaAs heterostructures. The disorder broadened Gaussian photoluminescence line due to localized electrons was found in the quantized Hall phase of the isolated multi-quanturn-well structure. On the other hand, the quantized Hall phase of weakly coupled multilayers emitted an unexpected asymmetrical line similar to that observed in metallic electron systems. We demonstrated that the observed asymmetry is caused by the partial population of extended electron states formed in the insulating quantized Hall phase due to spin-assisted interlayer percolation. A sharp decrease in the single-particle scattering time associated with these extended states was observed for the filling factor nu=2. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2978194]

Interior of tower, Carpenter Hall house, Wilston, Brisbane

View to landscape beyond through windows of upper level of tower.

Sunshading to exterior, Carpenter Hall house, Wilston, Brisbane

As seen from below.

View from interior, Carpenter Hall house, Wilston, Brisbane

View to landscape beyond from interior of house.

Interior under construction, Carpenter Hall house, Wilston, Brisbane

View to upper tower from lower section of house.

Interior under construction, Carpenter Hall house, Wilston, Brisbane

Triangular window openings to upper section of house.

Interior under construction, Carpenter Hall house, Wilston, Brisbane

Timber structure to upper floors, as seen from interior.

Interior of tower, Carpenter Hall house, Wilston, Brisbane

View to landscape beyond through windows of upper level of tower (shown open).

Internal staircase, Carpenter Hall house, Wilston, Brisbane

As seen from lower level of house.

View of Wilston, Carpenter Hall house, Wilston, Brisbane

As seen from interior of house.

North-west elevation, Carpenter Hall house, Wilston, Brisbane

House in foreground, with view to city beyond.

Exterior, Carpenter Hall house, Wilston, Brisbane

Exterior of house during construction.

North elevation, Carpenter Hall house, Wilston, Brisbane

Looking downhill to house during construction.