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The Laughlin state embodies a universal class of fractional quantum Hall effects arising in two-dimensional electron systems subjected to strong perpendicular magnetic fields. Conventionally described by a single-component wavefunction, the…

Bacteriorhodopsin (bR) is a light-driven proton pump. We use time-resolved crystallography at an X-ray free-electron laser to follow the structural changes in multiphoton-excited bR from 250 femtoseconds to 10 picoseconds. Quantum chemistry…

Energy transport in photosynthetic systems can be tremendously efficient. In particular we study exciton transport in the Fenna-Mathews-Olsen (FMO) complex found in green sulphur bacteria. The exciton dynamics and energy transfer efficiency…

Chemical Physics · Physics 2019-03-27 S. A. Oh , D. F. Coker , D. A. W. Hutchinson

Photosynthetic organisms use networks of chromophores to absorb sunlight and deliver the energy to reaction centres, where charge separation triggers a cascade of chemical steps to store the energy. We present a detailed model of the…

In pump-probe spectroscopy, two laser pulses are employed to garner dynamical information from the sample of interest. The pump initiates the optical process by exciting a portion of the sample from the electronic ground state to an…

Materials Science · Physics 2023-05-18 D. Sangalli , M. D'Alessandro , C. Attaccalite

New low-lying excitations are observed by inelastic light scattering at filling factors $\nu=p/(\phi p \pm 1)$ of the fractional quantum Hall regime with $\phi=4$. Coexisting with these modes throughout the range $\nu \leq 1/3$ are $\phi=2$…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. F. Hirjibehedin , A. Pinczuk , B. S. Dennis , L. N. Pfeiffer , K. W. West

We report two-photon resonance fluorescence of an individual semiconductor artificial atom. By non-linearly driving a single quantum dot via a two-photon transition, we probe the linewidth of the two-photon processes and show that, similar…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 P. -L. Ardelt , M. Koller , T. Simmet , L. Hanschke , A. Bechtold , A. Regler , J. Wierzbowski , H. Riedl , K. Müller , J. J. Finley

Non-Hermitian physics is reshaping our understanding of quantum systems by revealing states and phenomena without Hermitian counterparts. While non-Hermiticity is typically associated with gain-loss processes in open systems, we uncover a…

Materials Science · Physics 2025-12-17 Enrico Perfetto , Gianluca Stefanucci

Photosynthesis is arguably the fundamental process of Life, since it enables energy from the Sun to enter the food-chain on Earth. It is a remarkable non-equilibrium process in which photons are converted to many-body excitations which…

Soft Condensed Matter · Physics 2015-05-19 Felipe Caycedo-Soler , Ferney J. Rodríguez , Luis Quiroga , Neil F. Johnson

We studied, theoretically, the optical absorption spectra for a slightly asymmetric double quantum well (DQW), in the presence of electric and magnetic fields. Recent experimental results for a 10.18/3.82/9.61 nm GaAs Al(_{.33}…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Francisco Vera

We characterize spectroscopic and coherence properties of the 1451.37 nm excited-state zero-phonon line (ZPL) between the $^{3}F_{4}$ and the $^{3}H_{4}$ manifolds of a thulium-doped yttrium aluminum perovskite (Tm$^{3+}$:YAlO$_3$) crystal…

Spatially indirect excitons can be created when an electron and a hole, confined to separate layers of a double quantum well system, bind to form a composite Boson. Because there is no recombination pathway such excitons are long lived…

Mesoscale and Nanoscale Physics · Physics 2017-06-07 J. I. A. Li , T. Taniguchi , K. Watanabe , J. Hone , C. R. Dean

A quantum behavior of the light emitted by exciton polaritons excited in a pillar semiconductor microcavity with embedded quantum well is investigated. Considering the bare excitons and photon modes as coupled quantum oscillators allows for…

Mesoscale and Nanoscale Physics · Physics 2021-01-20 T. A. Khudaiberganov , S. M. Arakelian

Organic semiconducting polymers are currently of broad interest as potential low-cost materials for photovoltaic and light-emitting display applications. I will give an overview of our work in developing a consistent quantum dynamical…

Materials Science · Physics 2007-05-23 Eric R. Bittner , John Glen S. Ramon

The energy spectrum of a two-dimensional electron gas (2DEG) in the fractional quantum Hall regime interacting with an optically injected valence band hole is studied as a function of the filling factor $\nu$ and the separation $d$ between…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Arkadiusz Wojs , John J. Quinn

We investigate exciton bound-state formation and crystallization effects in two-dimensional electron-hole bilayers. Performing unbiased path integral Monte Carlo simulations all quantum and Coulomb correlation effects are treated on first…

Strongly Correlated Electrons · Physics 2012-11-30 J. Schleede , A. Filinov , M. Bonitz , H. Fehske

Optical chiral properties of a resonant hybrid photonic crystal (RHPC) are computed taking into account spin-orbit effect due to light-hole excitons perfectly confined in 2D quantum wells. The trends of the optical activity, expressed as a…

Mesoscale and Nanoscale Physics · Physics 2023-12-25 A. D'Andrea

Exciton-photon beats known as polariton Rabi oscillations in semiconductor microcavities are usually excited by short pulses of light. We consider a different pumping scheme, assuming a cw pumping of the Rabi oscillator from an exciton…

Mesoscale and Nanoscale Physics · Physics 2016-07-18 Nina S. Voronova , Andrei A. Elistratov , Yurii E. Lozovik

Cesium lead bromide (CsPbBr$_3$) is a representative material of the emerging class of lead halide perovskite semiconductors that possess remarkable optoelectronic properties. Its optical properties in the vicinity of the band gap energy…

On the basis of many-body {\it ab-initio} calculations, using single-shot G$_0$W$_0$ method and Bethe-Salpeter equation, we study phosphorene nanoribbons (PNRs) in the two typical zigzag and armchair directions. The electronic structure,…

Mesoscale and Nanoscale Physics · Physics 2016-12-16 Zahra Nourbakhsh , Reza Asgari