On the Dispersion Relation of Magnetoplasmons in a Planar Graphene-Based Superlattice

Dimensionality and heat transport in Si-Ge superlattices

We investigated how dimensionality affects heat transport in Si-Ge superlattices by computing the thermal conductivity of planar superlattices and arrays of Ge nanowires and nanodots embedded in Si. We studied superlattices with $\sim$10 nm periods using a fully atomistic Monte Carlo solution of the Boltzmann transport equation in the relaxation time approximation. We found that for periods larger than 4 nm, the room temperature cross-plane conductivity of planar superlattices with equally thick Si and Ge layers is larger than that of their nanowire and dot counterparts of similar sizes (up to…

Pseudospin Splitting of the Energy Spectrum of Planar Polytype Graphene-Based Superlattices

The energy spectrum of planar polytype graphene-based superlattices has been investigated. It is shown that their energy spectrum undergoes pseudospin splitting due to the asymmetry of quantum wells forming the superlattice potential profile.

Lattice mismatch induced ripples and wrinkles in planar graphene/boron nitride superlattices

A continuum theory to describe periodic ripple formation in planar graphene/boron nitride superlattices is formulated. Due to the lattice mismatch between the two materials, it is shown that flat superlattices are unstable with respect to ripple formation of appropriate wavelengths. A competition between bending energy and transverse stretching energy gives rise to an optimal ripple wavelength that depends on the superlattice pitch. The optimal wavelengths predicted by the continuum theory are in good agreement with atomic scale total energy calculations previously reported in Nandwana and Ert…

Tunable Negative Differential Resistance in Planer Graphene Superlattice Resonant Tunneling Diode

In this paper, we report on the controllable negative differential resistance (NDR) in a proposed planar graphene superlattice structure. High value of peak to valley ratio (PVR) is predicted. This is significant because of appearance of NDR with high PVR at low biases. Our finding is important since beside the other potential applications of the graphene, proposes implementation of the graphene based superlattice in electronic devices such as resonant tunneling diode and filters.

Accurate Gap Determination in Monolayer and Bilayer Graphene/h-BN Moire Superlattices

High mobility single and few-layer graphene sheets are in many ways attractive as nanoelectronic circuit hosts but lack energy gaps, which are essential to the operation of field-effect transistors. One of the methods used to create gaps in the spectrum of graphene systems is to form long period moire patterns by aligning the graphene and hexagonal boron nitride (h-BN) substrate lattices. Here, we use planar tunneling devices with thin h-BN barriers to obtain direct and accurate tunneling spectroscopy measurements of the energy gaps in single- and bi-layer graphene-h-BN superlattice structures…

设计具有间隙和倾斜的二维狄拉克锥在横向石墨烯超晶格中

Designer gapped and tilted Dirac cones in lateral graphene superlattices

通过双极波导阵列调控石墨烯中狄拉克锥的间隙和倾斜，利用超晶格紧束缚模型和转移矩阵计算验证，通过栅极电压调节实现太赫兹频段的狄拉克锥调控，为太赫兹应用提供新方法。