A tight binding and k.p study of monolayer stanene

Stanene is a single layer of tin atoms which has been discovered as an emerging material for quantum spin Hall related applications. In this paper, we present an accurate tight-binding model for single layer stanene near the Fermi level. We parameterized the onsite and hopping energies for the nearest, second nearest, and third nearest neighbor tight-binding method, both without and with spin orbital coupling. We derived the analytical solution for the →Γ and .→K points and numerically investigated the buckling effect on the material electronic properties. In these points of the reciprocal space, we also discuss a corresponding →k . →p description, obtaining the value of the →k . →p parameters both analytically from the tight-binding ones, and numerically, fitting the ab-initio dispersion relations. Our models provide a foundation for large scale atomistic device transport calculations

Performance analysis of the matrix pair method for blind channel identification

We study the estimation variance performance of the matrix pair (MP) method for estimating the impulse responses of multiple FIR channels driven by an unknown input sequence. A first-order perturbation analysis of the large-data-size performance of the MP method is presented and an explicit expression for the estimation variance is derived. Both the theoretical and simulation results are used to investigate the statistical performance of the MP method and a number of new insights are reveale

Detection of Protein Conformational Changes with Multilayer Graphene Nanopore Sensors

Detecting conformational change in protein or peptide is imperative in understanding their dynamic function and diagnosing diseases. Existing techniques either rely on ensemble average that lacks the necessary sensitivity or require florescence labeling. Here we propose to discriminate between different protein conformations with multiple layers of graphene nanopore sensors by measuring the effect of protein-produced electrostatic potential (EP) on electric transport. Using conformations of the octapeptide Angiotensin II obtained through molecular dynamics simulations, we show that the EP critically depends on the geometries of constituent atoms and each conformation carries a unique EP signature. We then, using quantum transport simulations, reveal that these characteristic EP profiles cause distinctive modulation to electric charge densities of the graphene nanopores, leading to distinguishable changes in conductivity. Our results open the potential of label-free, single-molecule, and real-time detection of protein conformational changes