This work comprises two main parts: creating and shaping narrowband, pulsed THz radiation in a table-top optical setup; and applying THz pulses to semiconductor nanostructures to study electron dynamics.
I developed a scheme to shape the THz output of a fanned-out periodically poled lithium niobate (PPLN) crystal. The pulses are...
Electron transport and relaxation may be substantially different in low-dimensional
systems compared to that observed in bulk material. In the present work, Monte Carlo
models are used for the solution to the Boltzmann transport equation, with scattering
rates calculated quantum mechanically for superlattice and quantum wells. Carrier
relaxation following optical...
Electron behavior in semiconductor materials critically determines electronic applications. Previous research has shown carrier temperature higher than the lattice temperature of LEDs due to energy differences in the quantum well. Study of these findings requires a novel set-up to dig out weak signal in a thermal-noise filled environment; analytical methods...
Intraexciton transitions in semiconductor quantum wells are modulated by strong and tunable few-cycle terahertz pulses. Time-resolved terahertz-pump and optical-probe measurements demonstrate that the 1s heavy-hole and light-hole exciton resonances undergo large-amplitude spectral modulations when the terahertz radiation is tuned near the 1s–2p intraexciton transition. The strong nonlinear optical transients exhibit...
Interactions of few-cycle terahertz pulses with the induced optical polarization in a quantum-well microcavity reveal that the lower and higher exciton-polariton modes together with the optically forbidden 2p-exciton state form a unique Lambda-type three-level system. Pronounced nonlinearities are observed via time-resolved strong-terahertz and weak-optical excitation spectroscopy and explained with a...
Quantum mechanics provides a conventional theory of scattering that is limited in
at least two ways: it focuses exclusively on the asymptotic regime and, in a more general
sense characteristic of all quantum descriptions, provides no concrete account of individual
particle evolution in spacetime. This is particularly true during the...
In this work we apply the finite temperature formulation of quantum
statistical mechanics to an analysis of the de Haas-van Alphen effect
in the quantum limit. A new expression is derived for the differential
magnetic susceptibility which clearly shows the individual contributions
of zero-temperature and non-zero temperature terms.
Interactions have...
One of the newer and rapidly developing approaches in quantum computing is based on "quantum walks," which are quantum processes on discrete space that evolve in either discrete or continuous time and are characterized by mixing of components at each step. The idea emerged in analogy with the classical random...
Measurement of a quantum system - the process by which an observer gathers information about it - provides a link between the quantum and classical worlds. The nature of this process is the central issue for attempts to reconcile quantum and classical descriptions of physical processes. Here, we show that...