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Messages - rebeda

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1
General Questions and Answers / Re: spin transfer torque - reg.
« on: December 27, 2019, 20:10 »
Dear sir,

I have been struggling to calculate the spin transfer torque of my molecular junction following the link

https://docs.quantumatk.com/tutorials/spin_transfer_torque/spin_transfer_torque.html

but, the calculations always gets aborted. I have attached the python file and the corresponding log file for your perusal.

will you please help me .

Regards,
rebeda

2
General Questions and Answers / Re: calculation of gate voltage Vs conductance for each bias voltages - reg.
« on: November 8, 2019, 18:28 »
Thank you so much for your reply!!!

I tried regenerating the error message for the third time, but to my surprise; it really worked!!!!!!

Will you please provide me the python script for calculating dI/dV from I-V data since I am not able to obtain dI/dV from the IV characteristics analyzer.

Regards,
Rebeda :D

3
General Questions and Answers / Re: calculation of gate voltage Vs conductance for each bias voltages - reg.
« on: November 5, 2019, 08:23 »
The python scrip show error when i set the drain source voltages as below.

# Drain-source voltages
drain_source_voltages = numpy.linspace(-0.05, 0.05, 11)*Volt

will you please point out where did I go wrong...
Regards,
Rebeda

4
General Questions and Answers / Re: calculation of gate voltage Vs conductance for each bias voltages - reg.
« on: November 4, 2019, 11:12 »
In the script obtained from the link for IV characteristics analysis, I am not able to calculate the required results for the gate voltages and drain source voltages below

# Gate-source voltages
gate_source_voltages = numpy.linspace(-1.0, 1.0, 41)*Volt

# Drain-source voltages
drain_source_voltages = numpy.linspace(-0.05, 0.05, 11)*Volt

But,  it worked quite well when I calculated for two drain-source voltages, set as

# Gate-source voltages
gate_source_voltages = numpy.linspace(-1.0, 1.0, 41)*Volt

# Drain-source voltages
drain_source_voltages = numpy.linspace(-0.05, 0.05, 2)*Volt

I have attached my input script for your perusal.

Regards,
Rebeda



5
General Questions and Answers / Re: calculation of gate voltage Vs conductance for each bias voltages - reg.
« on: November 3, 2019, 12:02 »
Thank you..!!!!!

https://docs.quantumwise.com/tutorials/graphene_nanoribbon_device/graphene_nanoribbon_device.html

In the above link suggested by you,  they have calculated IV characteristics for one to two drain source voltages at a given range of gate source voltages. Can I calculate the same for a range of drain source voltages in a single script?(say from -0.1 to 0.1  Vds  step size be 0.02)

Regards,
Rebeda

6
General Questions and Answers / Re: calculation of gate voltage Vs conductance for each bias voltages - reg.
« on: October 25, 2019, 22:33 »
Dear Sir,

Looking at the link below, I have successfully calculated conductance at different gate voltages.

https://docs.quantumwise.com/tutorials/graphene_nanoribbon_device/graphene_nanoribbon_device.html

How can I calculate the same for each of bias voltages (for 0.05 to 0.05 V(say))?
My aim is to draw coulomb diamond or conductance stability diagrams (2D contour plot) having Vg as the x-axis, Vb as y-axis and dI/dV as z-axis. Will you please help me.....  :(

Regards,
Rebeda

7
General Questions and Answers / Re: Script file for running batch job (quantum atk 2019.03)- reg.
« on: October 25, 2019, 20:45 »
Thank you for your reply..!!!!
 In the paper (link given below) they have used the LOE method for BDT (benzenedithiol) molecular junction. So, will this still hold good for the Extended DFT-NEGF-LOE formalism??

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.081405


Regards,
Rebeda

8
General Questions and Answers / Re: Extended DFT-NEGF-LOE formalism- reg.
« on: October 23, 2019, 11:19 »
Dear Sir,

LOE approximations is ideal for molecular system with weak electron-phonon coupling and whose density of states vary slowly around the Fermi energy .

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.72.201101

Will this still hold good for the Extended DFT-NEGF-LOE formalism??

Regards,
Rebeda


9
General Questions and Answers / Re: Script file for running batch job (quantum atk 2019.03)- reg.
« on: October 17, 2019, 08:17 »
Dear Sir,

With reference to the attached script file made for running batch job using ATK (version:2015.1) , will you please provide the new script file for execution of QuantumATK 2019.03 in batch?

Waiting for your kind reply..

Regards,
Rebeda

10
General Questions and Answers / Re: Script file for running batch job (quantum atk 2019.03)- reg.
« on: October 17, 2019, 08:12 »
Dear sir,

With reference to the attached script file for running batch job which was made for ATK 2015.1 version, will you please provide the new script file for execution of quantum ATK 2019.03 version in batch?

Waiting for your kind reply,

Regards,
Rebeda

11
General Questions and Answers / Re: spin transfer torque - reg.
« on: September 19, 2019, 10:32 »
Thank you Petr for your reply  :).  However I have some doubt regarding K point sampling.....

1. For my device relaxation and transport calculation (with bulk electrodes), I have considered 11 *11 * 1 and 2*2*100 k-points respectively. Is it ok?

2. If I consider 2*2*100 k-points  during relaxation as well as in transport calculation, I think the device seem to be 1 dimensional. At this point, what will be the nature of the electrodes (bulk or nanowire)?

12
General Questions and Answers / Re: spin transfer torque - reg.
« on: September 13, 2019, 08:30 »
Dear Sir,

I would like to know the status of my issue...... :( :( :( :'( :'( :'(

Regards,

Rebeda

13
General Questions and Answers / Re: spin transfer torque - reg.
« on: September 9, 2019, 11:50 »
Thank you for your kind reply. I have attached the concerned python and log files.
Regards,
Rebeda

14
General Questions and Answers / spin transfer torque - reg.
« on: September 9, 2019, 08:18 »
I have been trying to perform spin transfer torque calculation for my system following the step by step procedure as given in the link below:

https://docs.quantumwise.com/tutorials/spin_transfer_torque/spin_transfer_torque.html

But  every time in the middle of the Collinear Initial State calculations, it stops the execution showing the error below:

#Warning
#The provided initial state parameter has no pre-calculated data.
#Proceeding without setting an initial state

will you please help me....

Regards,
Rebeda

15
General Questions and Answers / Re: phonon transmission - reg.
« on: November 2, 2018, 09:09 »
I would like to know whether Caroli formula is used to calculate phonon transmission in atk ?
A link of the paper is given below where they have mentioned about caroli formula in page no. 4

https://aip.scitation.org/doi/10.1063/1.3531573

Thanking you!!!

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