Related papers: Transient dual-energy lasing in a semiconductor mi…
Using a combination of heat pulse and nuclear magnetic resonance techniques we demonstrate that the phase boundary separating the interlayer phase coherent quantum Hall effect at $\nu_T = 1$ in bilayer electron gases from the weakly coupled…
Spin-controlled lasers are highly interesting photonic devices and have been shown to provide ultra-fast polarization dynamics in excess of 200 GHz. In contrast to conventional semiconductor lasers their temporal properties are not limited…
The interaction of two laser pulses in an underdense plasma has proven to be able to inject electrons in plasma waves, thus providing a stable and tunable source of electrons. Whereas previous works focused on the "beatwave" injection…
We investigate, theoretically and numerically, the spin dynamics of a two-component exciton-polariton condensate created and sustained by non-resonant spin-polarized optical pumping of a semiconductor microcavity. Using the open-dissipative…
We explore the behaviour of a system which consists of a photon mode dipole coupled to a medium of two-level oscillators in a microcavity in the presence of decoherence. We consider two types of decoherence processes which are analogous to…
In the first part of this thesis I study the intermediate regime between ordinary lasing and a BEC of exciton polaritons. I take into account the fermionic structure of polaritons, treating the excitons as two-level systems coupled to a…
We present a systematic investigation of two-photon excitation processes in a GaAs-based microcavity in the strong-coupling regime. We observe second harmonic generation resonant to the upper and lower polariton level, which exhibits a…
For a circularly polarized single-color field at a central frequency of $2\omega$ the final electron momentum distribution upon strong field ionization does not carry any information about the phase of the initial momentum distribution.…
We first report that, for planar nematic MBBA, the electroconvection threshold voltage has a nonmonotonic temperature dependence, with a well-defined minimum, and a slope of about 0.12 V/degree near room temperature. Motivated by this…
The subbands of weakly coupled double-layer two dimensional electron gas systems consist of narrowly spaced pairs whose corresponding wavefunctions are symmetric and antisymmetric combinations of isolated layer subband wavefunctions. The…
Impulsive orientation of symmetric-top molecules excited by two-color femtosecond pulses is considered. In addition to the well-known transient orientation appearing immediately after the pulse and then reemerging periodically due to…
A new analytical potential energy surface (PES) has been constructed for H$_2^+$-He using a reproducing kernel Hilbert space (RKHS) representation from an extensive number of $ab initio$ energies computed at the multi-reference and full…
We investigate valley exciton dynamics in MoSe2 monolayers in polarization- and time-resolved photoluminescence (PL) spectroscopy at 4K. Following circularly polarized laser excitation, we record a low circular polarization degree of the PL…
In a standard semiconductor laser, electrons and holes recombine via stimulated emission to emit coherent light, in a process that is far from thermal equilibrium. Exciton-polariton condensates -- sharing the same basic device structure as…
We study the dissociation of H$_2$$^+$ in uv laser pulses by solving the non-Born-Oppenheimer time-dependent Schr\"{o}dinger equation as a function of the photon energy $\omega$ of the pulse. Significant enhancements of the dissociation…
Abstract: We report on emergence of an abnormal electronic polarization in twisted double bilayer WSe2 in antiparallel interface stacking geometry, where local centrosymmetry of atomic registries at the twist interface does not favor the…
We present a mode-locked semiconductor laser oscillator that emits few picosecond pulses (5-8ps at 379MHz repetition) with record peak power (112W) and pulse energy (0.5nJ) directly out of the oscillator (with no amplifier). To achieve this…
We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anti-crossing of the singlet (S) and m_S=+1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance…
Polariton lasing is demonstrated on the zero dimensional states of single GaAs/GaAlAs micropillar cavities. Under non resonant excitation, the measured polariton ground state occupancy is found to be as large as $10^{4}$. Changing the…
We experimentally explore the dynamic optical hysteresis of a semiconductor microcavity as a function of the sweep time. The hysteresis area exhibits a double power law decay due to the shot noise of the driving laser, which triggers…