Simulation of Single -Electron Charging Effects in Planar Nanoscale Devices
Nagaraja, Satyadev Hulikal
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/81311
Description
Title
Simulation of Single -Electron Charging Effects in Planar Nanoscale Devices
Author(s)
Nagaraja, Satyadev Hulikal
Issue Date
1999
Doctoral Committee Chair(s)
Leburton, Jean-Pierre
Department of Study
Electrical Engineering
Discipline
Electrical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Physics, Condensed Matter
Language
eng
Abstract
By expanding the model to incorporate electron spin under the Local Spin Density Approximation, the charging properties of the double quantum dot are investigated in terms of electron spin and interdot interaction. It is shown that both electrostatic and quantum mechanical coupling between the dots affect the charging properties. For weak interdot coupling, simultaneous or double charging of the two constituent dots occurs, as seen in recent experiments by Waugh and co-workers [2]. It is argued that the double charging model may be used to explain the phenomenon of pair tunneling in vertical dots observed by Ashoori et al. [3]. It is also shown that a spin polarized state can be realized for weak interdot coupling, with four electrons in each dot, a situation explained in terms of Hund's rules. Lastly, it is shown that a ferromagnetic-like state can be obtained for three electrons in the double-dot by varying the interdot coupling strength. As the interdot barrier is lowered, the pz states in the two dots couple to form a bonding state that is delocalized over both. For small energy spacing between the 1 s and the bonding states, the ground state for three electrons has an electron in the 1s state of each dot and the delocalized pz bonding state, with the spins of all the electrons aligned parallel.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
