scholarly journals A non-iterative method for vertex corrections of the Kubo formula for electric conductivity

2021 ◽  
Vol 258 ◽  
pp. 107551
Author(s):  
Yi-Wen Wei ◽  
Chao-Kai Li ◽  
Yuchuang Cao ◽  
Ji Feng
1990 ◽  
Vol 04 (02) ◽  
pp. 293-315 ◽  
Author(s):  
LIAO-YUAN CHEN ◽  
ZHAO-BIN SU

We present a derivation of the quantum Boltzmann equation for linear dc transport with a correction term to Mahan-Hansch's equations and derive a formal solution to it. Based on this formal solution, we find the electric conductivity can be expressed as the retarded current-current correlation. Therefore we explicitly demonstrate the equivalence of the two most important theoretical methods: quantum Boltzmann equation and Kubo formula.


Author(s):  
Galina Vasil’evna Troshina ◽  
Alexander Aleksandrovich Voevoda

It was suggested to use the system model working in real time for an iterative method of the parameter estimation. It gives the chance to select a suitable input signal, and also to carry out the setup of the object parameters. The object modeling for a case when the system isn't affected by the measurement noises, and also for a case when an object is under the gaussian noise was executed in the MatLab environment. The superposition of two meanders with different periods and single amplitude is used as an input signal. The model represents the three-layer structure in the MatLab environment. On the most upper layer there are units corresponding to the simulation of an input signal, directly the object, the unit of the noise simulation and the unit for the parameter estimation. The second and the third layers correspond to the simulation of the iterative method of the least squares. The diagrams of the input and the output signals in the absence of noise and in the presence of noise are shown. The results of parameter estimation of a static object are given. According to the results of modeling, the algorithm works well even in the presence of significant measurement noise. To verify the correctness of the work of an algorithm the auxiliary computations have been performed and the diagrams of the gain behavior amount which is used in the parameter estimation procedure have been constructed. The entry conditions which are necessary for the work of an iterative method of the least squares are specified. The understanding of this algorithm functioning principles is a basis for its subsequent use for the parameter estimation of the multi-channel dynamic objects.


2020 ◽  
pp. 67-78
Author(s):  
A. V. Shchegolkov ◽  
◽  
V. S. Yagubov ◽  
Yu. A. Khan ◽  
F. F. Komarov ◽  
...  

2018 ◽  
Vol 30 (10) ◽  
pp. 67-85
Author(s):  
V. Zhukov ◽  
◽  
O. Feodoritova ◽  
N. Novikova ◽  
◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document