current-voltage diagram
dear all I have done my project using Kwant and I have drawn a conductance-energy diagram for the system. The question I have is how can I get the current-voltage diagram? thanks Leo
dear Leo, If you have calculated the conductance G(E) of a 2 terminal device, the current I at finite voltage V is given by I = Integral dE G(E) [ f(E-mu_L) - f(E-mu_R) ] where mu_L and mu_R are the chemical potential of the two electrodes, f(E) is the Fermi function. mu_L - mu_R = eV where V is the voltage drop across the devices. Beware that this equation assumes a NON INTERACTING system and can lead to physically wrong results. (It neglects the electrostatic which becomes almost always relevant at finite bias). Best regards, Xavier
Le 30 juin 2020 à 13:37, <loojoo026@gmail.com> <loojoo026@gmail.com> a écrit :
dear all I have done my project using Kwant and I have drawn a conductance-energy diagram for the system. The question I have is how can I get the current-voltage diagram? thanks Leo
Thanks for your prompt reply Mr. Wintal. I did not calculate the Green function and obtained the G-E diagram using the transmission method introduced in the Green function class. Another method introduced in this class is conductance_matrix (), ( https://kwant-project.org/doc/1/reference/generated/kwant.solvers.common.Gre... ) which relates the current vector to the voltage vector. Can I use this method and get to the I-V diagram? I also want to check the temperature parameter in this system and see the device's behavior under different temperatures. thanks Leo On Tue, Jun 30, 2020 at 4:29 PM Xavier Waintal <xavier.waintal@cea.fr> wrote:
dear Leo,
If you have calculated the conductance G(E) of a 2 terminal device, the current I at finite voltage V is given by
I = Integral dE G(E) [ f(E-mu_L) - f(E-mu_R) ] where mu_L and mu_R are the chemical potential of the two electrodes, f(E) is the Fermi function. mu_L - mu_R = eV where V is the voltage drop across the devices.
Beware that this equation assumes a NON INTERACTING system and can lead to physically wrong results. (It neglects the electrostatic which becomes almost always relevant at finite bias).
Best regards, Xavier
Le 30 juin 2020 à 13:37, <loojoo026@gmail.com> <loojoo026@gmail.com> a écrit :
dear all I have done my project using Kwant and I have drawn a conductance-energy diagram for the system. The question I have is how can I get the current-voltage diagram? thanks Leo
Sorry, I made a mistake in my previous email I wrote the correction of the previous email below: Thanks for your prompt reply Mr. Wintal. I did not calculate the conductance and obtained the G-E diagram using the transmission method introduced in the Green function class. Another method introduced in this class is conductance_matrix (), ( https://kwant-project.org/doc/1/reference/generated/kwant.solvers.common.Gre... ) which relates the current vector to the voltage vector. Can I use this method and get to the I-V diagram? I also want to check the temperature parameter in this system and see the device's behavior under different temperatures. thanks Leo On Wed, Jul 1, 2020 at 12:48 PM Loo Joo <loojoo026@gmail.com> wrote:
Thanks for your prompt reply Mr. Wintal. I did not calculate the Green function and obtained the G-E diagram using the transmission method introduced in the Green function class. Another method introduced in this class is conductance_matrix (), ( https://kwant-project.org/doc/1/reference/generated/kwant.solvers.common.Gre... ) which relates the current vector to the voltage vector. Can I use this method and get to the I-V diagram? I also want to check the temperature parameter in this system and see the device's behavior under different temperatures. thanks Leo
On Tue, Jun 30, 2020 at 4:29 PM Xavier Waintal <xavier.waintal@cea.fr> wrote:
dear Leo,
If you have calculated the conductance G(E) of a 2 terminal device, the current I at finite voltage V is given by
I = Integral dE G(E) [ f(E-mu_L) - f(E-mu_R) ] where mu_L and mu_R are the chemical potential of the two electrodes, f(E) is the Fermi function. mu_L - mu_R = eV where V is the voltage drop across the devices.
Beware that this equation assumes a NON INTERACTING system and can lead to physically wrong results. (It neglects the electrostatic which becomes almost always relevant at finite bias).
Best regards, Xavier
Le 30 juin 2020 à 13:37, <loojoo026@gmail.com> <loojoo026@gmail.com> a écrit :
dear all I have done my project using Kwant and I have drawn a conductance-energy diagram for the system. The question I have is how can I get the current-voltage diagram? thanks Leo
Dear Sir, In the equation I = Integral dE G(E) [ f(E-mu_L) - f(E-mu_R) ] How I can know the individual mu_L and mu_R values which can be used to calculate I. Thanking You Ajit
participants (4)
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Loo Joo -
loojoo026＠gmail.com
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sahu.ajit92＠gmail.com -
Xavier Waintal