Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/37876
Title: Steady-state transport properties of anharmonic systems
Authors: THINGNA JUZAR YAHYA
Keywords: Quantum master equation, Modified Redfield solution, molecular junctions, phononics, spin drift-diffusion, spintronics
Issue Date: 18-Jan-2013
Source: THINGNA JUZAR YAHYA (2013-01-18). Steady-state transport properties of anharmonic systems. ScholarBank@NUS Repository.
Abstract: In this thesis we first focus on the reduced density matrix of an anharmonic system weakly connected to multiple heat baths. We show that the steady-state perturbative master equations are correct only up to second order in system-bath coupling and propose a novel modified Redfield solution (MRS) to capture the second order steady state effects. Next, we study phononics and develop two <i>sui generis</i> formulations to deal with anharmonic molecular junctions. Firstly, a weak-coupling formulation to study steady state and transient currents is developed. Secondly, nonequilibrium Green?s function techniques are employed to overcome the weak system-bath coupling approximation. Several examples and validations are provided for the proposed theories. Lastly, we study spin transport in: magnetic insulators using the MRS to analyze effects of system size and magnetic field and; semiconductors using the semi-classical spin drift-diffusion equations, which are applied to study the influence of device geometries on the spin-injection ratio.
URI: http://scholarbank.nus.edu.sg/handle/10635/37876
Appears in Collections:Ph.D Theses (Open)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
ThingnaJY.pdf731.29 kBAdobe PDF

OPEN

NoneView/Download

Page view(s)

207
checked on Dec 11, 2017

Download(s)

158
checked on Dec 11, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.