Branislav K. Nikolic

DNA Base-Specific Modulation of Microampere Transverse Edge Currents through a Metallic Graphene Nanoribbon with a Nanopore

We study two-terminal devices for DNA sequencing that consist of a metallic graphene nanoribbon with zigzag edges (ZGNR) and a nanopore in its interior through which the DNA molecule is translocated. Using the nonequilibrium Green functions combined with density functional theory, we demonstrate that each of the four DNA nucleobases inserted into the nanopore, whose edge carbon atoms are passivated by either hydrogen or nitrogen, will lead to a unique change in the device conductance. Unlike other recent biosensors based on transverse electronic transport through translocated DNA, which utilize small (of the order of pA) tunneling current across a nanogap or a nanopore yielding a poor signal-to-noise ratio, our device concept relies on the fact that in ZGNRs local current density is peaked around the edges so that drilling a nanopore away from the edges will not diminish the conductance. Inserting a nucleobase into the nanopore affects the charge density in the surrounding area, thereby modulating edge conduction currents whose magnitude is of the order of microampere at bias voltage 0.1 V. The proposed biosensors are not limited to ZGNRs and they could be realized with other nanowires supporting transverse edge currents, such as chiral GNRs or wires made of two-dimensional topological insulators.

Electron transport through a circular constriction

We calculate the conductance of a circular constriction of radius a in an insulating diaphragm which separates two conducting half spaces characterized by the mean free path l. Using the Boltzmann equation we obtain an answer for all values of the ratio

Nonequilibrium Spin Hall Accumulation in Ballistic Semiconductor Nanostructures

l/a.

Edge currents and nanopore arrays in zigzag and chiral graphene nanoribbons as a route toward high-ZTthermoelectrics

Our exact result interpolates between the Maxwell conductance in diffusive

Spin Hall current driven by quantum interferences in mesoscopic Rashba rings.

(l\ensuremath{\ll}a)

Spatial distribution of local currents of massless Dirac fermions in quantum transport through graphene nanoribbons

and the Sharvin conductance in ballistic

Modulating unpolarized current in quantum spintronics: Visibility of spin-interference effects in multichannel Aharonov-Casher mesoscopic rings

(l\ensuremath{\gg}a)

Giant thermoelectric effect in graphene-based topological insulators with heavy adatoms and nanopores.

transport regimes. Following Wexlers work, our main advance is to find the explicit form of the Greens function for the linearized Boltzmann operator. The formula for the conductance deviates by less than

Typical medium theory of Anderson localization: A local order parameter approach to strong-disorder effects

11%

First-principles quantum transport modeling of thermoelectricity in single-molecule nanojunctions with graphene nanoribbon electrodes

from the naive interpolation formula obtained by adding resistances in the diffusive and the ballistic regime.