The polarization dependence of the absorption coefficient for compressively and tensilely strained quantum wires is investigated as a function of strain, the lateral wire width, and the ratio between the wire and barrier widths. The results are markedly different from the case of an unstrained quantum wire and exhibit a significant variation with the sign and amount of built-in strain. In the c...

Quantum mechanical confinement and tunnelling play an important role in present and future generation decanano (sub 100 nm) MOSFETs and have to be properly taken into account in the simulation and design. Here we present a simple approach of introducing quantum corrections in a 3D drift diffusion simulation framework using the density gradient (DG) algorithm. We discuss the calibration of the D...

We investigate the photoresistance of a magnetically confined quantum wire in which microwave-coupled edge channels interfere at two pinning sites in the fashion of a Mach-Zehnder interferometer. The conductance is strongly enhanced by microwave power at B = 0 and develops a complex series of oscillations when the magnetic confinement increases. Both results are quantitatively explained by the ...

Recently, it has been shown that the thermoelectric figure of merit is strongly enhanced in quantum wells and superlattices due to two-dimensional carrier confinement. We predict that the figure of merit can increase even further in quantum well structures with free-surface or rigid boundaries. This additional increase is due to spatial confinement of acoustic phonons and corresponding modifica...

Electrically injected photonic crystal membrane light emitting microcavities with spatially localized optical gain are reported. The localization of the InGaAs quantum well inside the defect cavity of the photonic crystal allows for efficient coupling of the optical mode to the gain medium and reduces nonradiative carrier recombination. The use of a buried oxide layer under the semiconductor me...

• We have successfully synthesized Ge NPs in acetone using pulsed laser ablation. • The average size of NPs is found to decrease with the increase in laser pulse energy. • The NP number density increases with the increase in pulse energy of the ablation. • Size dependent blue luminescence has been observed from the synthesized Ge NPs. • The shift in the Raman peak position has been interpreted ...

We investigate non-perturbative features of a planar Chern-Simons gauge theory modeling the long-distance physics of quantum Hall systems, including a finite gapM for excitations. By formulating the model on a lattice we identify the relevant topological configurations and their interactions. For M > Mcr, the model exhibits an oblique confinement phase, which we identify with Laughlin’s incompr...

We present a simple analytical approach for the calculation of the built-in strain-induced and spontaneous potentials in nitride-based semiconductor quantum dots. We derive the built-in potentials and electric fields in terms of volume or surface integrals. We describe using a number of simplifying assumptions the general properties of piezoelectric and spontaneous fields in GaN/AlN and InN/GaN...

The exceptional electronic properties of graphene, with its charge carriers mimicking relativistic quantum particles and its formidable potential in various applications, have ensured a rapid growth of interest in this new material. We report on electron transport in quantum dot devices carved entirely from graphene. At large sizes (>100 nanometers), they behave as conventional single-electron ...

Wepresent a detailed experimental and theoretical Raman investigation of quantum confinement and laser-induced local thermal effects on hydrogenated nanocrystalline silicon with different nanocrystal sizes (3.6–6.2nm). The local temperature was monitored by measuring the Stokes/anti-Stokes peak ratio with the laser power density range from ~120 to 960kW/cm. In combination with the three-dimensi...