We use linearized time-dependent (current) density functional theory to study collective transitions between the two lowest subbands in GaAs/AlGaAs quantum wells. We focus on two particular systems, for both of which experimental results are available: a wide single square well, and a narrow asymmetric double quantum well. The aim is to calculate the frequency and linewidth of collective electr...

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 ...

Quantum cascade lasers (QCLs) employ the midand far-infrared intersubband radiative transitions available in semiconducting heterostructures. Through the precise design and construction of these heterostructures the laser characteristics and output frequencies can be controlled. When fabricated, QCLs offer a lightweight and portable alternative to traditional laser systems which emit in this fr...

We present an analytical approach to the problem of multiphoton absorption and Rabi oscillations in armchair graphene nanoribbon (AGNR) presence a time-oscillating strong electric field induced by light wave directed parallel ribbon axis. The two-dimensional Dirac equation for massless electron subject confinement is employed. In resonant approximation electron-hole pair production rate, associ...

Strained epitaxy has been shown to produce high quality InAs/GaAs quantum dot structures by single step epitaxy. While effective mass-based approaches have been used for quantum structures, the nature of the strain and quantum confinement in self-assembled dots is such that this is not a good approximation. In this letter, we use an eight-band k•p formalism to find the electronic spectra in InA...