Seminar"Original quantum treatment of inelastic interactions for the modeling of transport in 3D nano-structures"

Title: "Original quantum treatment of inelastic interactions for the modeling of transport in 3D nano-structures"

Speaker: Dr. Marc Bescond, LIMMS CNRS-IIS The University of Tokyo

Abstract:

In recent decades various transport approaches have been proposed to describe quantum effects occurring in nano-devices. Among them, the non-equilibrium Green’s function formalism (NEGF) is one of the most promising to treat inelastic interactions [1]. However, within this formalism description of inelastic scattering is usually based on the computationally demanding self-consistent Born approximation (SCBA). As an alternative method to SCBA, we have proposed an efficient technique, which is the so-called Lowest Order Approximation (LOA) coupled with Padé approximants [2]. In the seminar, we will introduce this approach and apply it to both electron and phonon transports using an atomistic code based on a tight-binding sp³d⁵s* model for electrons and holes, and a modified valence-force-field method for phonons. We will study quantum transport in nanowire transistors considering the main crystallographic transport directions (<100>, <110>, <111>), with uniform or discontinuous cross-sections, and including electron-phonon [3] and phonon-phonon [4] interactions. We will show that in most configurations, third-order LOA currents are enough to achieve a high agreement with SCBA results, while reducing the calculation time by about one order of magnitude.

References:

[1] H. Haug and A.-P. Jauho, Quantum Kinetics in Transport and Optics of Semiconductors (Springer, New York, 1996).

[2] Y. Lee, M. Lannoo, N. Cavassilas, M. Luisier, and M. Bescond, “Efficient quantum modeling of inelastic interactions in nanodevices,” Phys. Rev. B 93, 205411 (2016).

[3] Y. Lee, M. Bescond, N. Cavassilas, D. Logoteta, L. Raymond, M. Lannoo, M. Luisier, “Quantum treatment of phonon scattering for modeling of three-dimensional atomistic transport,” Phys. Rev. B (R) 95, 201412 (2017).

[4] Y. Lee, M. Bescond, D. Logoteta, N. Cavassilas, M. Lannoo, M. Luisier, “Anharmonic phonon-phonon scattering modeling of three-dimensional atomistic transport: An efficient quantum treatment,” Phys. Rev. B 97, 205447 (2018).