QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: yangzw1985 on June 1, 2009, 18:36

Title: a picture
Post by: yangzw1985 on June 1, 2009, 18:36

Hi,everyone!Attached is a picture, Can any one tell me how the dos can be display like this? In other words, HOW can I get the DOS picture OF VBM,CBM, FERMI LEVEL? Thanks!

Title: Re: a picture
Post by: Anders Blom on June 2, 2009, 11:06

The pictures show the "local density of states" as computed with the function calculateLocalDensityOfStates(), available in VNL under the analysis options for two-probe systems. What you do to get the different plots is to choose the energy at the Fermi level, at the top of the valence band, and bottom of the conduction band, respectively.

Store the results in a VNL file and use VNL to plot the results (Nanoscope).

Title: Re: a picture
Post by: yangzw1985 on June 2, 2009, 14:42

If we want to calculate the LDOS of a two probe system.How set the Quantum Numbers (k(A),K(B))? I have read the help file, but I can not understand it accurately. Can you give me some explain in detail? Thanks!

Title: Re: a picture
Post by: yangzw1985 on June 2, 2009, 18:02

Can anyone give me the answer as soon as possible? I have been looking forward to your reply!     Thanks in advance!

Title: Re: a picture
Post by: Anders Blom on June 2, 2009, 23:51

Please do not expect that every question on this forum can be answered within 2-3 hours, esp. considering time zones and office hours etc.

Just like the transmission coefficients, the DOS is broken down into contributions from each incident k-vector (kx,ky). ATK can calculate and plot (in VNL) the LDOS for each value of (kx,ky) and this is what is specified as the quantum numbers you mention. For a 1D system only the Gamma point (0,0) is relevant.

The quantum numbers are, as elsewhere in ATK, given in fractional coordinates, i.e. in the range -0.5 to 0.5. If you make the plot for a specific k-point outside the Gamma point, you usually do this because there appears to be a particularly interesting feature in the transmission coefficients for this k-point.

An example of how to specify the quantum numbers and run such a calculation is given here: http://quantumwise.com/documents/manuals/ATK-2008.10/chap.advtwoprobe.html#sect1.advtwoprobe.dos.

Title: Re: a picture
Post by: yangzw1985 on June 3, 2009, 00:46

Thank you for your reminding ,Anders Blom! I really appreciate your reply.Good job! :)