Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine

Journal Article · Wed Jan 07 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4905484· OSTI ID:22399240

Lesage, A. A. J.,; Griffiths, J. P.; Farrer, I.; Jones, G. A. C.; Ritchie, D. A.; Smith, C. G. ^[1]; Al-Taie, H.; Kelly, M. J. ^[1]; See, P. ^[2]

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1. Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)
2. National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW (United Kingdom)

A multiplexer technique is used to individually measure an array of 256 split gates on a single GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which requires the development of automated data analysis routines. An algorithm is developed to find the spacing between discrete energy levels, which form due to transverse confinement from the split gate. The lever arm, which relates split gate voltage to energy, is also found from the measured data. This reduces the time spent on the analysis. Comparison with estimates obtained visually shows that the algorithm returns reliable results for subband spacing of split gates measured at 1.4 K. The routine is also used to assess direct current bias spectroscopy measurements at lower temperatures (50 mK). This technique is versatile and can be extended to other types of measurements. For example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one another.

• OSTI ID: 22399240
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
77 NANOSCIENCE AND NANOTECHNOLOGY
ALGORITHMS
ALUMINIUM ARSENIDES
COMPARATIVE EVALUATIONS
DATA ANALYSIS
DIRECT CURRENT
ELECTRIC POTENTIAL
ENERGY LEVELS
GALLIUM ARSENIDES
HETEROJUNCTIONS
MAGNETIC FIELDS
MULTIPLEXERS
ONE-DIMENSIONAL CALCULATIONS
QUANTUM WIRES
ZEEMAN EFFECT