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QuantumATK => General Questions and Answers => Topic started by: jai on April 26, 2011, 19:45

Title: Current as a function of bias voltage sweep
Post by: jai on April 26, 2011, 19:45

Hello all,

Please tell me how to calculate the current as function of voltage sweep for the following two-probe system?  :(

With regards and thanks!

Title: Re: Current as a function of bias voltage sweep
Post by: Anders Blom on April 26, 2011, 21:38

This is described rather generally (using another system as example, but the principle is perfectly the same) here: http://quantumwise.com/publications/tutorials/mini-tutorials/98-i-v-curve-and-voltage-drop

Title: Re: Current as a function of bias voltage sweep
Post by: jai on April 27, 2011, 08:50

Dear sir,

Thank you for your kind timely response!

I tried this method also but couldn't get the result. May be i couldn't do it properly.
Is there any packages or module that need to be installed in the VNL directory for the same?
Looking forward to hear you again..

Title: Re: Current as a function of bias voltage sweep
Post by: Anders Blom on April 27, 2011, 09:47

No, nothing additional needs to be installed.

Title: Re: Current as a function of bias voltage sweep
Post by: jai on April 27, 2011, 20:23

Thank you sir..

Title: Re: Current as a function of bias voltage sweep
Post by: nori on April 28, 2011, 08:08

Dear jai,

I'd like to give you the procedure to obtain I-V curve as follows:

1. launch VNL,
2. execute "gnr_IV.py" with Job manager,
3. launch Custom Analyzer,
4. Choose Analyzers/I-V curve from the menu,
5. Drop "gnr_IV.nc" onto "Drop file here",

After doing the procedure, you can obtain the result like "custom_analyzer.PNG" ;)

Title: Re: Current as a function of bias voltage sweep
Post by: qnsyhanjiu on April 28, 2011, 09:37

dear,when comper the IV,how to add the spin?how to distinction the spinup or spindown?

Title: Re: Current as a function of bias voltage sweep
Post by: jai on May 2, 2011, 20:39

Dear nori Thanks,

Can you please provide me the script for the same curves you've shown in the fig.? I hope it will help me in writing a script for i-v curve..

WIth regards!

Title: Re: Current as a function of bias voltage sweep
Post by: nori on May 3, 2011, 13:02

Quote

Can you please provide me the script for the same curves you've shown in the fig.?

The example is as follows:
#---------------------------------------------------
bias_voltage = numpy.linspace(0.0,1.0,6)
current = []
for vb in bias_voltage:
    transmission_spectrum = nlread('gnr_IV.nc', object_id="Transmission"+str(vb))[0]
    current += [transmission_spectrum.current()]

print "-"*50
print "Bias Voltage [V]","\t","Current [nA]"
print "-"*50
for vb,i in zip(bias_voltage,current):
    print vb,"\t",i.inUnitsOf(Ampere)*(10**9)
#---------------------------------------------------