Topics

1

General Questions and Answers / creating a for loop for Id-Vg characteristics-URGENT

« on: April 29, 2011, 07:16 »

in an example given (li-h2-l2-iv  curve and voltage drop) a for loop was created,but it was observed that in t he structure a gate region wasn't designed,yet the gate voltage varied over certain value....in the gnreft on which i am working on,i created a gate region with a dielectric constant of 4...how can i incorporate this information in the for loop,what modifications should be made in the code to include this information or is it fine to use the code given without considering the gate parameters(dielectric constant and so on),as is seen the the tutorial(by just varying the gate voltage,AND NOT INCLUDING ANY DIELECTRIC PARAMETERS)...please do reply.....

2

General Questions and Answers / HELP IN RUNNING PROGRAMS IN A QUEUE

« on: April 28, 2011, 12:15 »

recently we have made use of the workstation license with mpi support(making use of all the 4 cores).but it was observed that only 1 program could be run at a time.also unlike the other versions other programs could not be put in a queue,which is a better usage of time unlike the problem that i am facing now...that is waiting for the present running program to get over and then manually sending the next program to run...could you help me in this regard that is i need your help in putting all the programs in a queue in the workstation,so that when one gets over,the next one automatically runs(like in the job manager).whta can i do for this?

3

General Questions and Answers / band gap determination

« on: April 8, 2011, 13:49 »

1.i  would like to know what is the band gap for the attached image (zig-zag GNR) since the band gap obtained using analyser script seems to be different.

2. how is the valence and conduction band maxima and minima estimated using the code. (since they taken at different z-coordinate points).

3. what is the difference between band gap(just below the valence and conduction band maxima and minima) and direct band gap(obtained at yet another z-coordinate point) obtained using the analyser

4

General Questions and Answers / linear doping

« on: March 31, 2011, 08:10 »

How can LINEAR DOPING be implemented using atk?

5

General Questions and Answers / Id vs Vbias for GNRFET-HELP

« on: March 23, 2011, 07:41 »

While trying to obtain the output characteristics for a gnrfet(made with doped zigzag gnr) i was not able to obtain the desired characteristics.i have attached the characteristics that i am obtaining for the same.could you please help me out in this matter.the output chara to be obtained is one where the current saturates after some point(as is observed in all gnrfets),but for me its the same characteristics as the transfer characteristics..what could be the MISTAKE that i might be making during the simulations....

6

General Questions and Answers / query regarding brillouin zones

« on: March 14, 2011, 11:25 »

with reference to the query posted earlier by myself,i would also like to know what order are the symbols (G,X,Y,Z)arranged in the the bandstructure?(as in graphene where the BZ symbols are arranged in the form G K M K')

7

General Questions and Answers / query regarding brillouin zone parameters in bandstructure

« on: March 14, 2011, 07:21 »

when finding out the band structure for a zigzag gnr its seen that gamma and z point is taken as default(x and y points can be used(when the unit cell lattice is taken)).But it was observed in several papers that the band structure(even the complex bandstructure ) is observed from gamma to x point,but when i have tried to make use of it,the band structure obtained doesnt match with the results obtained in several papers,but the bandstructure obtained taking gamma and z points are very(almost) similar.I wanted to know why is this difference obtained in the structure obtained(i.e the result desired is obtained in the paper from gamma to x,and for me when simulating from gamma to z.)?it would be helpful to know what does the z point(in BZ) refer to in the simulation(in atk).

8

General Questions and Answers / query regarding mtj

« on: March 9, 2011, 14:11 »

In the MTJ builder, how can the number of layers in barriers, inner layer separation of surface layers, electrode/oxygen distance under surface layers for Fe/HfO2/Fe MTJ,if the number of layers in the electrodes is taken as 4 and the number of layers in barrier is taken as 6 .
   

9

General Questions and Answers / query regarding gate and bias voltage

« on: March 9, 2011, 06:28 »

i want to apply a gate voltage of +0.1V and the bias voltage range is from 0 to +0.7(in case of GNRFET).i wanted to know that when i give +values of these voltages in the required fields in ATK the results are obtained for the negative values....thus how to obtain the results for the +values of Vbias and Vgate...since that is what is neede(symmetrise option is available but i need it for the value of voltage that i apply for i.e for example if i give  Vbias=0.1,the value of current and the plot is obtained for -0.1 in the I-V curve)

10

General Questions and Answers / query regarding complex band structure

« on: March 7, 2011, 06:08 »

It is seen that the complex band structure(especially the real part of it)is plotted using dots.On zooming in,since these are in the form of dots its not easy to differentiate..is it possible to obtain the band structure as solid lines,which will be of use and has better clarity.

Also,the real part is in terms of k x (alpha)/pi;i wanted to know what the alpha term represents.coz i wanted the real part axis as 2 x pi/(lattice constant);but here its given as mentioned above.