2006/07/06 by Alessandro Pioda, A. Pioda, S. Kicin +10 · 1 citation
Chemistry · Computer Science · Physics and Astronomy · #Analytical Chemistry (journal) #Atomic physics #Chemistry #Condensed matter physics #Conductance #Doping #Electron #Impurity #Materials science #Optics #Optoelectronics #Physics #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum point contact #Quantum well #Scanning capacitance microscopy #Scanning electron microscope #Scanning gate microscopy #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.75.045433
published as Phys. Rev. B 75, 045433 (2007)
arxiv created 2006/07/06 · openalex publication_date 2007/01/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A quantum point contact (QPC) patterned on a two-dimensional electron gas is investigated with a scanning gate setup operated at a temperature of 300\phantom\rule0.3em0exmK. The conductance of the point contact is recorded while the local potential is modified by scanning the tip. Discrete charging of traps induced by the local potential is observed as a stepwise conductance change of the constriction. By selectively changing the state of some of these traps, it is possible to observe changes in the transmission of the QPC. The lateral position of such traps is determined, and their density is estimated to be below 50\phantom\rule0.3em0exper\phantom\rule0.3em0ex\ensuremathμm2, corresponding to less than 1% of the doping concentration.