Related papers: Why a magnetized quantum wire can act as an active…
We theoretically predict a nonequilibrium phase transition in quantum spin systems induced by a laser, which provides a purely quantum-mechanical way of coherently controlling magnetization. Namely, when a circularly polarized laser is…
We have investigated experimentally and theoretically the far-infrared (FIR) absorption of gated, deep-mesa-etched GaAs/Al$_x$Ga$_{1-x}$As quantum wires. To overcome Kohn's theorem we have in particular prepared double-layered wires and…
Ballistic quantum wires are exposed to longitudinal profiles of perpendicular magnetic fields composed of a spike (magnetic barrier) and a homogeneous part. An asymmetric magnetoconductance peak as a function of the homogeneous magnetic…
We present a general mathematical procedure to handle interactions described by a Morse potential in the presence of a strong harmonic excitation. We account for permanent and field-induced terms and their gradients in the dipole moment…
We propose a magnetomechanical device that exhibits many properties of a laser. The device is formed by a nanocantilever and dynamically polarized paramagnetic nuclei of a solid sample in a strong external magnetic field. The corresponding…
The equilibrium properties and interminiband transitions for Hartree-interacting two-dimensional electron gas in a one-dimensional chain of planar quantum rings subjected to a transverse homogeneous magnetic field are examined theoretically…
The influence of Gaussian laser pulses on the transport through molecular wires is investigated within a tight-binding model for spinless electrons including correlation. Motivated by the phenomenon of coherent destruction of tunneling for…
In condensed matter systems, interactions between collective modes offer avenues for nonlinear coherent manipulation of coupled excitations and quantum phases. Antiferromagnets, with their inherently coupled magnon modes, provide a…
Quantum wire networks (``quantum crossbars'', QCB) represent a 2D grid formed by superimposed crossing arrays of parallel conducting quantum wires, molecular chains or metallic single-wall carbon nanotubes. QCB coupled only by capacitive…
We analize theoretically the dynamics of N electrons localized in a semiconductor quantum ring under a train of phase-locked infrared laser pulses. The pulse sequence is designed to control the total angular momentum of the electrons. The…
Plasmas may be used as gain media for amplifying intense lasers, and external magnetic fields may be applied to improve the performance. For mid-infrared lasers, the requisite magnetic field is on megagauss scale, which can already be…
Problems of strongly interacting electrons can be greatly simplified by reducing them to effective quantum spin models. The initial step is renormalization of the Hamiltonian into a lower energy subspace. The positive and negative U Hubbard…
A doped graphene layer in the integer quantum Hall regime reveals a highly unusual particle-hole excitation spectrum, which is calculated from the dynamical polarizability in the random phase approximation. We find that the elementary…
In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent…
Magnons, the quanta of collective spin excitations in magnetically ordered materials, have distinct properties that make them uniquely appealing for quantum information applications. They can have ultra-small wavelengths down to the…
Coherent phonons can greatly vary light-matter interaction in semiconductor nanostructures placed inside an optical resonator on an ultrafast time scale. For an ensemble of quantum dots as active laser medium phonons are able to induce a…
The prospect of using light to probe or manipulate quantum materials has become an active area of interest. Here, we investigate a quantum wire -- treated as a finite-sized one-dimensional electron gas -- that is coupled to a single…
We investigate the nonlinear interaction between a relativistically strong laser beam and a plasma in the quantum regime. The collective behavior of the electrons is modeled by a Klein-Gordon equation, which is nonlinearly coupled with the…
We investigate the influence of external laser excitations on the average current through bridged molecules. For the computation of the current, we use a numerically very efficient formalism that is based on the Floquet solutions of the…
The density functional theory is used to study the electronic structure of a quantum wire in a magnetic field. The Kohn-Sham equations are solved numerically for different values of electron densities and filling factors. The critical…