März

Bild des Monats März 2022

Resistivity calculation using MD-KKR approach

The ab initio calculation of the temperature dependent electrical resistivity of materials still represents a great challenge. Methods such as the lowest order variational approximation to the Boltzmann transport equation are widely used, while the Keldysch formalism has been employed in our workgroup. (https://doi.org/10.1103/PhysRevB.96.165121) However, both of these formalisms require a prior calculation of the electron-phonon interaction self-energy. To eliminate this need, the MD-KKR formalism has recently been devised. A MD simulation of the material in question (here: copper) is carried out to obtain screenshots of a material at a certain temperature. These screenshots are used as input structures for calculating the transmission with the KKR code. From the tranmission, temperature dependent resistivity and electron-phonon self-energies are easily obtainable.
Also $k_\parallel$ dependent transmissions are obtained in this way and are displayed for different temperatures. At 0 K this transmission is 1 if states exist at the Fermi energy for this $k_\parallel$ vector and 0 otherwise. With increasing temperature the transmission of these states decreases due to the electron-phonon scattering effects within the material.

Dieses Bild wurde eingereicht von Prof. Dr. Christian Heiliger.

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