2017/06/30 by Ousmane Ly, Rodolfo A. Jalabert, Steven Tomsovic +1 · 23 citations
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Condensed matter physics #Conductance #Density of states #Force Microscopy Techniques and Applications #Local density of states #Microscopy #Optics #Physics #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Scanning capacitance microscopy #Scanning confocal electron microscopy #Scanning gate microscopy #Transmission (telecommunications) #Transmission coefficient #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.96.125439
published in Physical review. B./Physical review. B 96(12) (American Physical Society) · 16 pages, 9 figures
openalex publication_date 2017/09/29 · arxiv created 2017/12/21 · arxiv updated 2017/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Scanning gate microscopy images from measurements made in the vicinity of quantum point contacts were originally interpreted in terms of current flow. Some recent work has analytically connected the local density of states to conductance changes in cases of perfect transmission, and at least qualitatively for a broader range of circumstances. In the present paper, we show analytically that in any time-reversal invariant system there are important deviations that are highly sensitive to imperfect transmission. Nevertheless, the unperturbed partial local density of states can be extracted from a weakly invasive scanning gate microscopy experiment, provided the quantum point contact is tuned anywhere on a conductance plateau. A perturbative treatment in the reflection coefficient shows just how sensitive this correspondence is to the departure from the quantized conductance value and reveals the necessity of local averaging over the tip position. It is also shown that the quality of the extracted partial local density of states decreases with increasing tip radius.