QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: huangshenjie on March 7, 2013, 13:32

Title: a problem about transmission spectrum
Post by: huangshenjie on March 7, 2013, 13:32

Dear all, when I calculated the transmission spectrum of my MTJ, I noticed that the transmission spectrums calculated through different self-energy calculators are quite different as well as the currents. Which calculator should I choose?

And in order to obtain a reasonable current, which is the reasonable value of the energies? Is numpy.linspace(-2,2,101)*eV OK??

Title: Re: a problem about transmission spectrum
Post by: kstokbro on March 7, 2013, 15:14

We recommend the RecursionSelfEnergy . You may reduce the infinitesimal parameter for the transmission spectrum to 1e-9 to increase the accuracy.
Current methods are only accurate down to ~1e-15 transmission, however, if you want to resolve transmissions below the noise level of 1e-15 you may use TransmissionEigenstate and sum up the eigenvalues of the transmission states.

As for the required energy resolution it is system dependent. Plot the transmission spectrum, and check if there are resonances and how well the resonances are described.