47 citations · 232 across the 16 of their papers we have counts for
8 papers · 1 filter
Switching between attractive and repulsive Coulomb-interaction-mediated drag in an ambipolar GaAs/AlGaAs bilayer device
B. Zheng, A. F. Croxall, J. Waldie +5
We present measurements of Coulomb drag in an ambipolar GaAs/AlGaAs double quantum well structure that can be configured as both an electron-hole bilayer and a hole-hole bilayer, w…
Landau level spin diode in a GaAs two dimensional hole system
O. Klochan, A. R. Hamilton, K. das Gupta +3
We have fabricated and characterized the Landau level spin diode in GaAs two dimensional hole system. We used the hole Landau level spin diode to probe the hyperfine coupling betwe…
Fabrication and characterisation of ambipolar devices on an undoped AlGaAs/GaAs heterostructure
J. C. H. Chen, D. Q. Wang, O. Klochan +7
We have fabricated AlGaAs/GaAs heterostructure devices in which the conduction channel can be populated with either electrons or holes simply by changing the polarity of a gate bia…
Ultra-shallow quantum dots in an undoped GaAs/AlGaAs 2D electron gas
W. Y. Mak, F. Sfigakis, K. Das Gupta +7
We report quantum dots fabricated on very shallow 2-dimensional electron gases, only 30 nm below the surface, in undoped GaAs/AlGaAs heterostructures grown by molecular beam epitax…
Linear non-hysteretic gating of a very high density 2DEG in an undoped metal-semiconductor-metal sandwich structure
K. Das Gupta, A. F. Croxall, W. Y. Mak +5
Modulation doped GaAs-AlGaAs quantum well based structures are usually used to achieve very high mobility 2-dimensional electron (or hole) gases. Usually high mobilities ($>10^{7}{…
Distinguishing impurity concentrations in GaAs and AlGaAs, using very shallow undoped heterostructures
W. Y. Mak, K. Das Gupta, H. E. Beere +3
We demonstrate a method of making a very shallow, gateable, undoped 2-dimensional electron gas. We have developed a method of making very low resistivity contacts to these structur…
On the Zero-Bias Anomaly in Quantum Wires
S. Sarkozy, F. Sfigakis, K. Das Gupta +4
Undoped GaAs/AlGaAs heterostructures have been used to fabricate quantum wires in which the average impurity separation is greater than the device size. We compare the behavior of…
Low Temperature Transport in Undoped Mesoscopic Structures
S. Sarkozy, K. Das Gupta, C. Siegert +6
Using high quality undoped GaAs/AlGaAs heterostructures with optically patterned insulation between two layers of gates, it is possible to investigate very low density mesoscopic r…