Causal self-energies for NEGF modelling of quantum nanowires

4th Workshop on Theory, Modelling and Computational Methods for Semiconductors

物理学;计算机科学

Barker, J.^1 ; Martinez, A.^2 ; Aldegunde, M.^2 ; Valin, R.^2

School of Engineering, University of Glasgow, G12 8LT, United Kingdom^1

College of Engineering, University of Swansea, United Kingdom^2

关键词: Density of state;    Dissipative devices;    Electron phonon;    Electron phonon scattering;    Non-equilibrium green functions;    Quantum nanowires;    Self energy;    Silicon nanowire field-effect transistors;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/526/1/012001/pdf
DOI  :  10.1088/1742-6596/526/1/012001

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Electron-phonon scattering is shown to increase dramatically at small nanowire cross-sections so that the transport is not ballistic. Non-ballistic dissipative device modelling requires the full complexity of the non-equilibrium Green Function (NEGF) method. The role of causality in obtaining spectral sum rule-conserving approximations to the electron-phonon self-energies is demonstrated and applications given for wrap-round gate silicon nanowire field effect transistors. Causality violations give erroneous density of states and current densities.