Related papers: Optical coherence storage in dark exciton states u…
The dark exciton state in semiconductor quantum dots constitutes a long-lived solid-state qubit which has the potential to play an important role in implementations of solid-state based quantum information architectures. In this work, we…
The effects of the electron-phonon interaction on optical excitations can be understood in terms of exciton-phonon coupling, and require a careful treatment in low-dimensional materials with strongly bound excitons or strong electron-hole…
We report on the generation of time-bin entangled photon pairs from a semiconductor quantum dot via pulsed resonant biexciton generation. Based on theoretical modeling we optimized the duration of the excitation pulse to minimize the…
We report the demonstration of phase coherence and control for the recently developed "light storage" technique. Specifically, we use a pulsed magnetic field to vary the phase of atomic spin excitations which result from the deceleration…
Acoustic waves can serve as memory for optical information, however, acoustic phonons in the GHz regime decay on the nanosecond timescale. Usually this is dominated by intrinsic acoustic loss due to inelastic scattering of the acoustic…
We study quantum compression and decompression of light pulses that carry quantum information using a photon-echo quantum memory technique with controllable inhomogeneous broadening of an isolated atomic absorption line. We investigate…
Semiconductor quantum dots can emit antibunched, single photons on demand with narrow linewidths. However, the observed linewidths are broader than lifetime measurements predict, due to spin and charge noise in the environment. This noise…
Stimulated two-photon emission by Bose-condensed excitons accompanied by a coherent two-exciton recombination, i.e., by simultaneous recombination of two excitons with opposite momenta leaving unchanged the occupation numbers of excitonic…
We discuss how excitons can affect the generation of coherent radial breathing modes in ultrafast spectroscopy of single wall carbon nanotubes. Photoexcited excitons can be localized spatially and give rise to a spatially distributed…
Recent ultrafast optical experiments show that excitons in large biological light-harvesting complexes are coupled to molecular vibration modes. These high-frequency vibrations will not only affect the optical response, but also drive the…
The present review is devoted to our recent studies on the excitonic motion in photosynthetic systems. In photosynthesis, the light photon is absorbed to create an exciton in the antenna complex of the photosynthetic pigments. This exciton…
We discuss a model of quantum photosynthesis with degeneracy in the light-harvesting system. We consider interaction of excitons in chromophores with light and phonons (vibrations of environment). These interactions have dipole form but are…
Dark excitons are of fundamental importance in a broad range of contexts, but are difficult to study using conventional optical spectroscopy due to their weak interaction with light. We show how coherent multidimensional spectroscopy can…
We demonstrate a one to one correspondence between the polarization state of a light pulse tuned to neutral exciton resonances of single semiconductor quantum dots and the spin state of the exciton that it photogenerates. This is…
We investigate the exciton dynamics in an exactly solvable two-band model for semiconductors. The model incorporates light-matter, electron-electron and electron-phonon interactions, and captures exciton formation as well as the transition…
The idea that excitonic state (electronic) coherences are of fundamental importance to natural photosynthesis gained popularity when, a decade ago, slowly dephasing quantum beats were observed in the two-dimensional electronic spectra of…
We analyze a stimulated revival (echo) effect for the breathing modes of the atomic oscillations in optical lattices. The effect arises from the dephasing due to the weak anharmonicity being partly reversed in time by means of additional…
We report a measurement of the spin-echo decay of a single electron spin confined in a semiconductor quantum dot. When we tip the spin in the transverse plane via a magnetic field burst, it dephases in 37 ns due to the Larmor precession…
Well controlled nonlinear interactions between light field pulses and single atoms could be used to implement optical quantum information technologies based on qubits encoded in superpositions of coherent states of light. Here, we…
The visibility of two-photon interference is limited by the indistinguishability of the photons. In the cascaded emission of a three-level system, such as a single quantum dot, the indistinguishability of each photon in the pair is…