The competition between resonant optical excitation of Rydberg states of atoms and their strong, long-range van der Waals interaction results in spatial ordering of Rydberg excitations in a two-dimensional lattice gas, as observed in a recent experiment of Schau\ss{} et al. [Nature (London) 491, 87 (2012)]. Here we use semiclassical Monte Carlo simulations to obtain stationary states for hundreds of atoms in finite-size lattices. We show the formation of regular spatial structures of Rydberg excitations in a system of increasing size, and find highly sub-Poissonian distribution of the number of Rydberg excitations characterized by a large negative value of the Mandel $Q$ parameter which is nearly independent of the system size.The competition between resonant optical excitation of Rydberg states of atoms and their strong, long-range van der Waals interaction results in spatial ordering of Rydberg excitations in a two-dimensional lattice gas, as observed in a recent experiment of Schau\ss{} et al. [Nature (London) 491, 87 (2012)]. Here we use semiclassical Monte Carlo simulations to obtain stationary states for hundreds of atoms in finite-size lattices. We show the formation of regular spatial structures of Rydberg excitations in a system of increasing size, and find highly sub-Poissonian distribution of the number of Rydberg excitations characterized by a large negative value of the Mandel $Q$ parameter which is nearly independent of the system size.

arXiv:1306.0320Physical Review AOct 28, 201326 citations

Emergence of spatial order in highly interacting Rydberg gases

João D. Rodrigues, Hugo Terças, Luís F. Gonçalves +2 more

We describe the emergence of strong spatial correlations, akin to liquidlike behavior and crystallization effects, in low- (one- and two-)dimensional gases of cold Rydberg atoms. The presence of an external electric field permanently polarizes the atoms, which became highly correlated due to the long-range dipole-dipole interaction. We describe a theoretical approach particularly suited for strongly coupled systems and numerically obtain both the two-particle distribution function and the static structure factor. The experimental implementation of such highly interacting systems is discussed, including detailed calculations of the interaction strength for different Rydberg states. The results provide insights into many-body effects associated with strongly interacting Rydberg atoms, including the possibility of observing highly ordered phases.We describe the emergence of strong spatial correlations, akin to liquidlike behavior and crystallization effects, in low- (one- and two-)dimensional gases of cold Rydberg atoms. The presence of an external electric field permanently polarizes the atoms, which became highly correlated due to the long-range dipole-dipole interaction. We describe a theoretical approach particularly suited for strongly coupled systems and numerically obtain both the two-particle distribution function and the static structure factor. The experimental implementation of such highly interacting systems is discussed, including detailed calculations of the interaction strength for different Rydberg states. The results provide insights into many-body effects associated with strongly interacting Rydberg atoms, including the possibility of observing highly ordered phases.

arXiv:1712.09879Physical Review AFeb 22, 20181 citation

Quantum phases of Rydberg atoms in two-dimensional arrays

Rhine Samajdar, Wen Wei Ho, Hannes Pichler +2 more

Bulletin of the American Physical SocietyMar 16, 20210 citations

Measurements of the ion velocity distribution in an ultracold neutral plasma derived from a cold, dense Rydberg gas

Scott Bergeson, Mary Lyon

We report measurements of the ion velocity distribution in an ultracold neutral plasma derived from a dense, cold Rydberg gas in a MOT. The Rydberg atoms are excited using a resonant two-step excitation pathway with lasers of 4 ns duration. The plasma forms spontaneously and rapidly. The rms width of the ion velocity distribution is determined by measuring laser-induced fluorescence (LIF) of the ions. The measured excitation efficiency is compared with a Monte-Carlo wavefunction calculation, and significant differences are observed. We discuss the conditions for blockaded Rydberg excitation and the subsequent spatial ordering of Rydberg atom domains. While the blockade interaction is greater than the Rabi frequency in portions of the atomic sample, no evidence for spatial ordering is observed.We report measurements of the ion velocity distribution in an ultracold neutral plasma derived from a dense, cold Rydberg gas in a MOT. The Rydberg atoms are excited using a resonant two-step excitation pathway with lasers of 4 ns duration. The plasma forms spontaneously and rapidly. The rms width of the ion velocity distribution is determined by measuring laser-induced fluorescence (LIF) of the ions. The measured excitation efficiency is compared with a Monte-Carlo wavefunction calculation, and significant differences are observed. We discuss the conditions for blockaded Rydberg excitation and the subsequent spatial ordering of Rydberg atom domains. While the blockade interaction is greater than the Rabi frequency in portions of the atomic sample, no evidence for spatial ordering is observed.

arXiv:1601.07439Bulletin of the American Physical SocietyJan 27, 20160 citations

Quantum dynamics of three-dimensional Rydberg-atom systems

MinHyuk Kim, Hansub Hwang, Heekun Nho +2 more

Bulletin of the American Physical SocietyJun 5, 20200 citations

Q

parameter which is nearly independent of the system size.