Computer Lab: Difference between revisions

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===Density of states using equilibrium retarded Green function===
===Density of states using equilibrium retarded Green function===
*[http://www.physics.udel.edu/~bnikolic/teaching/phys824/MATLAB/dos_negf.m dos_negf.m]  
*[http://www.physics.udel.edu/~bnikolic/teaching/phys824/MATLAB/dos_negf.m dos_negf_closed.m] computes DOS for finite 1D wire
*[http://www.physics.udel.edu/~bnikolic/teaching/phys824/MATLAB/graphene_dos.m graphene_dos.m]  
*[http://www.physics.udel.edu/~bnikolic/teaching/phys824/MATLAB/dos_negf.m dos_negf_open.m] computes DOS for finite 1D wire attached to single reservoir
*[http://www.physics.udel.edu/~bnikolic/teaching/phys824/MATLAB/graphene_dos.m graphene_dos.m] computes DOS for a piece of graphene


===Subband structure of graphene nanoribbons using tight-binding models===
===Subband structure of graphene nanoribbons using tight-binding models===

Revision as of 15:49, 20 September 2012

Unix Training

MATLAB Training

Hands-on tutorials by Instructor

Hands-on Lab tutorials by MathWorks

Reference

Books and notes

Implementation Tools

MATLAB Scripts

Electron density in nanowires using equilibrium density matrix

DOS of disordered nanowire using eigenvalues and Anderson localization of eigenfunctions

Density of states using equilibrium retarded Green function

Subband structure of graphene nanoribbons using tight-binding models

  • 8zgnr.m (pedestrian code for 8-ZGNR only)

Quantum transport in 1D nanowires using NEGF

  • qt_1d.m (code to compute the conductance and total and local density of states of a 1D nanowire, with possible potential barriers or impurities, attached to two semi-infinite electrodes)

Tunneling magnetoresistance in 1D models

Spin-transfer torque in 1D models

Klein tunneling in graphene heterojunctions

  • M.-H. Liu and K. Richter, Efficient quantum transport simulation for bulk graphene heterojunctions, arXiv:1206.0266.

MATLAB functions

  • matrix_exp.m (Exponential, or any other function with small changed in the code, of a Hermitian matrix)
  • visual_graphene_H.m (For a given tight-binding Hamiltonian on the honeycomb lattice, function plots position of carbon atoms and draws blue lines to represent hoppings between them; red circles to represent on-site potential between them; and cyan lines to represent the periodic boundary conditions; it can be used to test if the tight-binding Hamiltonian of graphene is set correctly); This function calls another three function which should be placed in the same directory (or in the path): atomCoord.m, atomPosition.m, and constrainView.m
  • self_energy.m (Self-energy of the semi-infinite ideal metallic lead modeled on the square tight-binding lattice - the code shows how to convert analytical formulas of the lead surface Green function into a working program)

Density functional theory using GPAW

Hands-on tutorials by CAMd at Denmark Technical University

Hands-on tutorials by Instructor

  • Band structure of Fe
  • Subbandstructure of graphene nanoribbons
  • Subband structure of carbon nanotubes

NEGF-DFT using GPAW

Zero-bias transmission function of single-molecule nanojunctions

I-V curve of magnetically ordered zigzag GNR

  • D. A. Areshkin and B. K. Nikolić, I-V curve signatures of nonequilibrium-driven band gap collapse in magnetically ordered zigzag graphene nanoribbon two-terminal devices, Phys. Rev. B 79, 205430 (2009). [PDF]
  • J. Chen, K. S. Thygesen, and K. W. Jacobsen, Phys. Rev. B 85, 155140 (2012). [PDF]