Related papers: Giant Rydberg Excitons in Cuprous Oxide
We have performed two-photon excitation via the 6P3/2 state to n=50-80 S or D Rydberg state in Bose-Einstein condensates of rubidium atoms. The Rydberg excitation was performed in a quartz cell, where electric fields generated by plates…
Excitons -- two-particle correlated electron-hole pairs -- are the dominant low-energy optical excitation in the broad class of semiconductor materials, which range from classical silicon to perovskites, and from two-dimensional to organic…
A mechanism for amplification of weak quadrupole transitions of Rydberg excitons in Cu$_2$O by a plasmonic nanostructure is investigated. The theoretical description of exciton-plasmon interaction is presented and a field averaging…
The bound electron-hole pairs known as excitons govern the optical properties of insulating solids. While their behavior in equilibrium is well-understood theoretically, the nonequilibrium regime at high excitation densities-where phenomena…
We have studied the associative ionization of a Rydberg atom and a ground state atom in an ultracold Rydberg gas. The measured scattering cross section is three orders of magnitude larger than the geometrical size of the produced molecule.…
Rydberg atoms provide a wide range of possibilities to tailor interactions in a quantum gas. Here we report on Rydberg excitation of Bose-Einstein condensed 87Rb atoms. The Rydberg fraction was investigated for various excitation times and…
For low-density plasmas, the classical limit described by the Debye-H\"uckel theory is still considered as an appropriate description even though a clear experimental proof of this paradigm is lacking due to the problems in determining the…
Rydberg atoms with principal quantum number n >> 1 have exaggerated atomic properties including dipole-dipole interactions that scale as n^4 and radiative lifetimes that scale as n^3. It was proposed a decade ago to take advantage of these…
The emergence of photonic quantum correlations is typically associated with emitters strongly coupled to a photonic mode. Here, we show that semiconductor Rydberg excitons, which are only weakly coupled to a free-space light mode can…
Quantum optics based on highly excited atoms, also known as Rydberg atoms, has cemented itself as a powerful platform for the manipulation of light at the few-photon level. The Rydberg blockade, resulting from the strong interaction between…
The laser-excitation of Rydberg atoms in ultracold gases is often described assuming that the atomic motion is frozen during the excitation time. We show that this frozen gas approximation can break down for atoms that are held in optical…
Electron quasiparticles play a crucial role in simplifying the description of many-body physics in solids with surprising success. Conventional Landau's Fermi-liquid and quasiparticle theories for high-temperature superconducting cuprates…
We experimentally realize Rydberg excitations in Bose-Einstein condensates of rubidium atoms loaded into quasi one-dimensional traps and in optical lattices. Our results for condensates expanded to different sizes in the one-dimensional…
We investigate the influence of the appearance of excitonic states on van der Waals interactions among two Rydberg atoms. The atoms are assumed to be in different Rydberg states, e.g., in the $|ns\rangle$ and $|np\rangle$ states. The…
Assemblies of highly excited Rydberg atoms in an ultracold gas can be set into motion by a combination of van-der-Waals and resonant dipole-dipole interactions. Thereby, the collective electronic Rydberg state might change due to…
The concept of \textit{optical} exciton - a photo-excited bound electron-hole pair within a crystal - is routinely used to interpret and model a wealth of excited-state phenomena in semiconductors. Beside originating sub-band gap signatures…
The strong Coulomb interaction in 2D materials facilitates the formation of tightly bound excitons and charge-ordered phases of matter. A prominent example is the formation of a crystalline phase from free charges due to mutual Coulomb…
One of the most striking features of the strong interactions between Rydberg atoms is the dipole blockade effect, which allows only a single excitation to the Rydberg state within the volume of the blockade sphere. Here we present a method…
The exceptionally large polarisability of highly excited Rydberg atoms (six orders of magnitude higher than ground-state atoms) makes them of great interest in fields such as quantum optics, quantum computing, quantum simulation and…
We demonstrate experimentally that a single Rb atom excited to the $79d_{5/2}$ level blocks the subsequent excitation of a second atom located more than $10 \mu\rm m$ away. The observed probability of double excitation of $\sim 30%$ is…