We study transport of indirect excitons in GaAs/AlGaAs coupled quantum wells in linear lattices created by laterally modulated gate voltage. The localization-delocalization transition for transport across the lattice was observed with reducing lattice amplitude or increasing exciton density. The exciton interaction energy at the transition is close to the lattice amplitude. These results are co...

A state-of-the-art variational wave function incorporating Jastrow-type exciton-phonon correlations, the global-local Ansatz, is utilized to elucidate exciton-phonon correlations in a generalized form of the Holstein Hamiltonian with the simultaneous presence of diagonal and off-diagonal exciton-phonon coupling. Much lowered ground-state energies are found for the global-local Ansatz when compa...

We present a many-body theory for the interactions of two-dimensional exciton-polaritons beyond Born approximation. Taking into account Gaussian quantum fluctuations via Bogoliubov theory, we find that exciton-exciton scattering is strongly renormalized by light-matter coupling and acquires an inverse logarithmic dependence on lower polariton energy. As result, interaction strength may be enhan...

Third-generation photovolatics require demanding cost and power conversion efficiency standards, which may be achieved through efficient exciton multiplication. Therefore, generating more than one electron-hole pair from the absorption of a single photon has vast ramifications on solar power conversion technology. Unlike their bulk counterparts, irradiated semiconductor quantum dots exhibit eff...

The band-edge optical response of transition metal dichalcogenides, an emerging class of atomically thin semiconductors, is dominated by tightly bound excitons localized at the corners of the Brillouin zone (valley excitons). A fundamental yet unknown property of valley excitons in these materials is the intrinsic homogeneous linewidth, which reflects irreversible quantum dissipation arising fr...

A phenomenological coupled exciton model is proposed in order to characterize optical excitations in extended dendrimers. An onsite exciton state is assigned at each phenyl rings and a nearest neighbor hopping integral which obeys the Gaussian distribution is considered between the exciton states. The decreasing optical excitation energy with respect to the dendrimer size indicates the presence...

Understanding multiple-exciton generation (MEG) in quantum dots (QDs) requires in-depth measurements of transient exciton dynamics. Because MEG typically faces competing ultrafast energy-loss intra-band relaxation, it is of central importance to investigate the emerging time-scale of the MEG kinetics. Here, we present ultrafast spectroscopic measurements of the MEG in PbS QDs via probing the gr...

Time-resolved photoluminescence ~PL! spectroscopy has been used to study the radiative recombination of excitons bound to ionized donors in GaN doped with both Mg and Si at concentrations of 5310/cm and 1.5310/cm, respectively. Low temperature (T;10K) time-resolved, as well as integrated PL spectra, identify an ionized donor-bound ~Si! exciton peak (DX) approximately 11.5 meV below and a neutra...

The two-dimensional vibrational response of the disordered strongly fluctuating OH exciton band in liquid water is investigated using a new simulation protocol. The direct nonlinear exciton propagation generalizes the nonlinear exciton equations to include nonadiabatic time dependent Hamiltonian and transition dipole fluctuations. The excitonic picture is retained and the large cancellation bet...