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Item Ion modes in dense ionized plasmas through nonadiabatic molecular dynamics(American Physical Society, 2020-10-27) Davis, R. A.; Angermeier, W. A.; Hermsmeier, R. K. T.; White, T. G.We perform nonadiabatic simulations of warm dense aluminum based on the electron-force field (EFF) variant of wave-packet molecular dynamics. Comparison of the static ion-ion structure factor with density functional theory (DFT) is used to validate the technique across a range of temperatures and densities spanning the warm densematter regime. Focusing on a specific temperature and density (3.5 eV, 5.2 g/cm3), we report on differences in the dynamic structure factor and dispersion relation across a variety of adiabatic and nonadiabatic techniques. We find the dispersion relation produced with EFF is in close agreement with the more robust and adiabatic Kohn-Sham DFT.Item Quantum Network of Atom Clocks: A Possible Implementation with Neutral Atoms(2016) Kómár, Péter; Topcu, T.; Kessler, E. M.; Derevianko, Andrei; Vuletic, V.; Ye, J.; Lukin, Mikhail D.We propose a protocol for creating a fully entangled Greenberger-Horne-Zeilinger-type state of neutral atoms in spatially separated optical atomic clocks. In our scheme, local operations make use of the strong dipole-dipole interaction between Rydberg excitations, which give rise to fast and reliable quantum operations involving all atoms in the ensemble. The necessary entanglement between distant ensembles is mediated by single-photon quantum channels and collectively enhanced light-matter couplings. These techniques can be used to create the recently proposed quantum clock network based on neutral atom optical clocks. We specifically analyze a possible realization of this scheme using neutral Yb ensembles.Item Zeptonewton force sensing with nanospheres in an optical lattice(2016) Ranjit, Gambhir; Cunningham, Mark S.; Casey, Kirsten; Geraci, Andrew A.Optically trapped nanospheres in high vacuum experience little friction and hence are promising for ultrasensitive force detection. Here we demonstrate measurement times exceeding 10(5) s and zeptonewton force sensitivity with laser-cooled silica nanospheres trapped in an optical lattice. The sensitivity achieved exceeds that of conventional room-temperature solid-state force sensors by over an order of magnitude, and enables a variety of applications including electric-field sensing, inertial sensing, and gravimetry. The particle is confined at the antinodes of the optical standing wave, and by studying the motion of a particle which has been moved to an adjacent trapping site, the known spacing of the antinodes can be used to calibrate the displacement spectrum of the particle. Finally, we study the dependence of the trap stability and lifetime on the laser intensity and gas pressure, and examine the heating rate of the particle in vacuum without feedback cooling.Item Two-Particle Interference of Electron Pairs on a Molecular Level(2016) Waitz, M.; Metz, D.; Lower, J.; Schober, C.; Keiling, M.; Pitzer, Martin; Mertens, K.; Martins, M.; Viefhaus, J.; Klumpp, S.; Weber, T.; Schmidt-Boecking, H.; Schmidt, L. Ph H.; Morales, F.; Miyabe, S.; Rescigno, T. N.; McCurdy, C. W.; Martin, F.; Williams, J. B.; Schoeffler, M. S.; Jahnke, Till; Doerner, ReinhardWe investigate the photodouble ionization of H-2 molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasiparticle consisting of both electrons (i.e., the "dielectron") does. The work highlights the fact that nonlocal effects are embedded everywhere in nature where many-particle processes are involved.Item Ionization potentials of superheavy elements No, Lr, and Rf and their ions(2016) Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.; Kramida, A.We predict ionization potentials of superheavy elements No, Lr, and Rf and their ions using a relativistic hybrid method that combines configuration interaction (CI) with the linearized coupled-cluster approach. Extensive study of the completeness of the four-electron CI calculations for Hf and Rf was carried out. As a test of theoretical accuracy, we also calculated ionization potential of Yb, Lu, Hf, and their ions, which are homologues of the superheavy elements of this study.