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Title: Diffusive and Ballistic Magnetoquantum Conductances of Single and Tunnel-Coupled Double Quantum Well Wires.

Abstract

Abstract not provided.

Authors:
;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1157554
Report Number(s):
SAND2007-1716J
523597
DOE Contract Number:
DE-AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Asian Journal of Physics; Related Information: Proposed for publication in Asian Journal of Physics.
Country of Publication:
United States
Language:
English

Citation Formats

Lyo, Sungkwun K., and Huang, Danhong. Diffusive and Ballistic Magnetoquantum Conductances of Single and Tunnel-Coupled Double Quantum Well Wires.. United States: N. p., 2007. Web.
Lyo, Sungkwun K., & Huang, Danhong. Diffusive and Ballistic Magnetoquantum Conductances of Single and Tunnel-Coupled Double Quantum Well Wires.. United States.
Lyo, Sungkwun K., and Huang, Danhong. Thu . "Diffusive and Ballistic Magnetoquantum Conductances of Single and Tunnel-Coupled Double Quantum Well Wires.". United States. doi:.
@article{osti_1157554,
title = {Diffusive and Ballistic Magnetoquantum Conductances of Single and Tunnel-Coupled Double Quantum Well Wires.},
author = {Lyo, Sungkwun K. and Huang, Danhong},
abstractNote = {Abstract not provided.},
doi = {},
journal = {Asian Journal of Physics},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • We study the ballistic and diffusive magnetoquantum transport using a typical quantum point contact geometry for single and tunnel-coupled double wires that are wide (less than or similar to1 mum) in one perpendicular direction with densely populated sublevels and extremely confined in the other perpendicular (i.e., growth) direction. A general analytic solution to the Boltzmann equation is presented for multisublevel elastic scattering at low temperatures. The solution is employed to study interesting magnetic-field dependent behavior of the conductance such as a large enhancement and quantum oscillations of the conductance for various structures and field orientations. These phenomena originate from themore » following field-induced properties: magnetic confinement, displacement of the initial- and final-state wave functions for scattering, variation of the Fermi velocities, mass enhancement, depopulation of the sublevels and anticrossing (in double quantum wires). The magnetoconductance is strikingly different in long diffusive (or rough. dirty) wires from the quantized conductance in short ballistic (or clean) wires. Numerical results obtained for the rectangular confinement potentials in the growth direction are satisfactorily interpreted in terms of the analytic solutions based on harmonic confinement potentials. Some of the predicted features of the field-dependent diffusive and quantized conductances are consistent with recent data from GaAs/AlxGa1-xAs double quantum wires.« less
  • We study the ballistic and diffusive magnetoquantum transport using a typical quantum point contact geometry for single and tunnel-coupled double wires that are wide ({approx}<1 {mu}m) in one perpendicular direction with densely populated sublevels and extremely confined in the other perpendicular (i.e., growth) direction. A general analytic solution to the Boltzmann equation is presented for multisublevel elastic scattering at low temperatures. The solution is employed to study interesting magnetic-field dependent behavior of the conductance such as a large enhancement and quantum oscillations of the conductance for various structures and field orientations. These phenomena originate from the following field-induced properties: magneticmore » confinement, displacement of the initial- and final-state wave functions for scattering, variation of the Fermi velocities, mass enhancement, depopulation of the sublevels and anticrossing (in double quantum wires). The magnetoconductance is strikingly different in long diffusive (or rough, dirty) wires from the quantized conductance in short ballistic (or clean) wires. Numerical results obtained for the rectangular confinement potentials in the growth direction are satisfactorily interpreted in terms of the analytic solutions based on harmonic confinement potentials. Some of the predicted features of the field-dependent diffusive and quantized conductances are consistent with recent data from GaAs/Al{sub x}Ga{sub 1-x}As double quantum wires.« less
  • We study the low-temperature in-plane magnetoresistance of tunnel-coupled quasi-one-dimensional quantum wires. The wires are defined by two pairs of mutually aligned split gates on opposite sides of a < 1 micron thick AlGaAs/GaAs double quantum well heterostructure, allowing independent control of their widths. In the ballistic regime, when both wires are defined and the field is perpendicular to the current, a large resistance peak at ~6 Tesla is observed with a strong gate voltage dependence. The data is consistent with a counting model whereby the number of subbands crossing the Fermi level changes with field due to the formation ofmore » an anticrossing in each pair of 1D subbands.« less
  • The authors study the low-temperature in-plane magnetoresistance of tunnel-coupled quasi-one-dimensional quantum wires. The wires are defined by two pairs of mutually aligned split gates on opposite sides of a {le} 1 micron thick AlGaAs/GaAs double quantum well heterostructure, allowing independent control of the width of each quantum well. In the ballistic regime, when both wires are defined and the field is perpendicular to the current, a large resistance peak at {approximately}6 Tesla is observed with a strong gate voltage dependence. The data is consistent with a counting model whereby the number of subbands crossing the Fermi level changes with fieldmore » due to the formation of an anticrossing in each pair of 1D subbands.« less