Spin Transport in Armchair Silicene Nanoribbon on the Substrate: The Role of Charged Impurity

Abstract

In this work, electrical and spin properties of armchair silicene nanoribbon (ASiNR) in the presence of charged impurity are studied. The non‐equilibrium Green's function along with multi‐orbital tight‐binding is applied to obtain the transmission probability. Different types of spin transmission probability in the ASiNR on a substrate are investigated. The charged impurities are located in the underlying substrate. Spin‐flip along the channel is calculated by using the spin transmission probability. The spin diffusion length in ASiNR for differently charged impurities is obtained and compared with the mean free path.

Non-equilibrium Green’s function approach for simulation asymmetric source-drain silicene-based photodetectors

“…The main part of the devices (nanoribbon) is chosen to have 13 silicon atoms (N) in width (∼2.35 nm), which is in the 3 m+1 family, 30 iterative supercells (n) in length (∼20 nm), and a total of 780 silicon atoms (N tot ). This long enough length ensures that charge carriers move ballistically between the source and drain [24,25]. The bond length, the buckling distance, and the lattice constant of SiNR are 2.3, 0.44, and 3.86 Å, respectively [9].…”

Giant Spin Lifetime Anisotropy and Spin-Valley Locking in Silicene and Germanene from First-Principles Density-Matrix Dynamics

“…Understanding spin dynamics and transport in materials is of key importance for spintronics and information technologies, and one key metric of useful spin dynamics is τ s . Compared with graphene, for which τ s has been extensively studied, ,, the τ s of silicene and germanene have not been measured and the existing few theoretical studies were done based on relatively simple models , without realistic interactions with phonons and impurities. Recently, we developed a first-principles density-matrix (FPDM) method with quantum descriptions of the scattering processes between electron–phonon (e-ph), electron–impurities (e-i), and electron–electron to simulate spin–orbit-mediated spin dynamics in solid-state systems with arbitrary symmetry. , We applied this method to disparate materials and obtained good agreement with experiments. ,, This new method enables us to predict the τ s of silicene and germanene at finite temperatures with realistic interactions with the environment without introducing any simplified model or empirical parameters, for picosecond to microsecond time scale simulation.…”

“…Understanding spin dynamics and transport in materials is of key importance for spintronics and information technologies, and one key metric of useful spin dynamics is τ s . Compared with graphene, for which τ s has been extensively studied, 6,25,26 the τ s of silicene and germanene have not been measured and the existing few theoretical studies were done based on relatively simple models 27,28 without realistic interactions with phonons and impurities. Recently, we developed a first-principles density-matrix (FPDM) method with quantum descriptions of the scattering processes between electron−phonon (e-ph), electron−impurities (e-i), and electron−electron to simulate spin−orbit-mediated spin dynamics in solid-state systems with arbitrary symmetry.…”

Giant Spin Lifetime Anisotropy and Spin-Valley Locking in Silicene and Germanene from First-Principles Density-Matrix Dynamics

“…Understanding spin dynamics and transport in materials is of key importance for spintronics and spin-based quantum information science, and one key metric of useful spin dynamics is spin lifetime τ s . Compared with graphene, of which τ s has been extensively studied experimentally and theoretically 6,25,26 , τ s of silicene and germanene have not been measured and the existing few theoretical studies were done based on relatively simple models 27,28 , which do not include realistic interactions with phonons and impurities. Recently we developed a First-Principles Density-Matrix (FPDM) approach with quantum descriptions of scattering processes between electron-phonon (e-ph), electron-impurities (e-i) and electron-electron, to simulate spin-orbit mediated spin dynamics in general solid-state systems with arbitrary symmetry 29,30 .…”