2005/03/31 by F. E. Camino, Fernando Camino, Wei Zhou +2
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Quantum and electron transport phenomena #Semiconductor materials and devices #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.72.155313
published as Phys. Rev. B 72, 155313 (2005) · published version
openalex publication_date 2005/10/19 · arxiv created 2005/10/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report experiments on a quantum electron interferometer fabricated from high mobility, low density AlGaAs∕GaAs heterostructure material. In this device, a nearly circular electron island is defined by four front gates deposited in etched trenches. The island is separated from the two-dimensional (2D) electron bulk by two nearly open constrictions. In the quantum Hall regime, two counterpropagating edge channels are coupled by tunneling in the constrictions, thus forming a closed electron interference path. For several fixed front gate voltages, we observe periodic Aharonov-Bohm interference oscillations in four-terminal resistance as a function of the enclosed flux. The oscillation period \ensuremathΔB gives the area of the interference path S via the quantization condition S=h∕e\ensuremathΔB. We experimentally determine the dependence of S on the front gate voltage, and find that the Aharonov-Bohm quantization condition does not require significant corrections due to the confining potential. These results can be interpreted as a constant integrated compressibility of the island with respect to the front gates. We also analyze experimental results using two classical electrostatics models: one modeling the 2D electron density due to depletion from an etch trench, and another modeling the gate voltage dependence of the electron density profile in the island.