DSpace Community:http://hdl.handle.net/10203/234662017-04-21T10:32:46Z2017-04-21T10:32:46ZThe Holometer: an instrument to probe Planckian quantum geometryChou, AaronGlass, HenryGustafson, H. RichardHogan, CraigKamai, Brittany L.Kwon, OhkyungLanza, RobertMcCuller, LeeMeyer, Stephan S.Richardson, JonathanStoughton, ChrisTomlin, RayWeiss, Rainerhttp://hdl.handle.net/10203/2232502017-04-17T07:27:32Z2017-03-01T00:00:00ZTitle: The Holometer: an instrument to probe Planckian quantum geometry
Authors: Chou, Aaron; Glass, Henry; Gustafson, H. Richard; Hogan, Craig; Kamai, Brittany L.; Kwon, Ohkyung; Lanza, Robert; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Ray; Weiss, Rainer
Abstract: This paper describes the Fermilab Holometer, an instrument for measuring correlations of position variations over a four-dimensional volume of space-time. The apparatus consists of two co-located, but independent and isolated, 40 m power-recycled Michelson interferometers, whose outputs are cross-correlated to 25 MHz. The data are sensitive to correlations of differential position across the apparatus over a broad band of frequencies up to and exceeding the inverse light crossing time, 7.6 MHz. A noise model constrained by diagnostic and environmental data distinguishes among physical origins of measured correlations, and is used to verify shot-noise-limited performance. These features allow searches for exotic quantum correlations that depart from classical trajectories at spacelike separations, with a strain noise power spectral density sensitivity smaller than the Planck time. The Holometer in current and future configurations is projected to provide precision tests of a wide class of models of quantum geometry at the Planck scale, beyond those already constrained by currently operating gravitational wave observatories.2017-03-01T00:00:00ZMHz gravitational wave constraints with decameter Michelson interferometersChou, Aaron S.Gustafson, RichardHogan, CraigKamai, BrittanyKwon, OhkyungLanza, RobertLarson, Shane L.McCuller, LeeMeyer, Stephan S.Richardson, JonathanStoughton, ChrisTomlin, RaymondWeiss, Rainerhttp://hdl.handle.net/10203/2232552017-04-17T07:27:43Z2017-03-01T00:00:00ZTitle: MHz gravitational wave constraints with decameter Michelson interferometers
Authors: Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; Larson, Shane L.; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Weiss, Rainer
Abstract: A new detector, the Fermilab Holometer, consists of separate yet identical 39-meter Michelson interferometers. Strain sensitivity achieved is better than 10(-21) / root Hz between 1 to 13 MHz from a 130-h data set. This measurement exceeds the sensitivity and frequency range made from previous high frequency gravitational wave experiments by many orders of magnitude. Constraints are placed on a stochastic background at 382 Hz resolution. The 3 sigma upper limit on Omega(GW), the gravitational wave energy density normalized to the closure density, ranges from 5.6 x 10(12) at 1 MHz to 8.4 x 10(15) at 13 MHz. Another result from the same data set is a search for nearby primordial black hole binaries (PBHB). There are no detectable monochromatic PBHBs in the mass range 0.83-3.5 x 10(21) g between the Earth and the Moon. Projections for a chirp search with the same data set increase the mass range to 0.59 - 2.5 x 10(25) g and distances out to Jupiter. This result presents a new method for placing limits on a poorly constrained mass range of primordial black holes. Additionally, solar system searches for PBHBs place limits on their contribution to the total dark matter fraction.2017-03-01T00:00:00ZTunable, Endotaxial Inclusion of Crystalline Pt-Based Nanoparticles Inside a High-Quality Bronze TiO2 MatrixKim, Sung JooLei, PeiZhang, KuiZhou, ChangGraham, George W.Pan, Xiaoqinghttp://hdl.handle.net/10203/2232542017-04-17T07:27:41Z2017-03-01T00:00:00ZTitle: Tunable, Endotaxial Inclusion of Crystalline Pt-Based Nanoparticles Inside a High-Quality Bronze TiO2 Matrix
Authors: Kim, Sung Joo; Lei, Pei; Zhang, Kui; Zhou, Chang; Graham, George W.; Pan, Xiaoqing
Abstract: A series of high-quality bronze titanium oxide films containing endotaxially embedded Pt-based nanoparticles was fabricated using pulsed laser deposition under various oxygen partial pressures (0 to 50 mTorr). We found that morphological control over the embedded Pt nanoparticles is possible by varying the oxygen partial pressure during growth. We also found that the titanium oxide matrix plays an important role in controlling composition, shape, and distribution of the endotaxially embedded Pt-based nanoparticles over this range of oxygen partial pressure by affecting (1) the formation of a segregated layer of Pt Ti alloy nanoparticles, in addition to the pure Pt nanoparticles, under vacuum, (2) the generation of crystallographic twinning, steps, and kinks within the Pt nanoparticles, and (3) the localized precipitation of Pt nanoparticles spatially confined and morphologically adapted to the extended defects within the matrix.2017-03-01T00:00:00ZUniversal entanglement spectra of gapped one-dimensional field theoriesCho, Gil YoungLudwig, Andreas W. W.Ryu, Shinseihttp://hdl.handle.net/10203/2232522017-04-17T07:27:38Z2017-03-01T00:00:00ZTitle: Universal entanglement spectra of gapped one-dimensional field theories
Authors: Cho, Gil Young; Ludwig, Andreas W. W.; Ryu, Shinsei
Abstract: We discuss the entanglement spectrum of the ground state of a ( 1+ 1)- dimensional system in a gapped phase near a quantum phase transition. In particular, in proximity to a quantum phase transition described by a conformal field theory ( CFT), the system is represented by a gapped Lorentz invariant field theory in the " scaling limit" ( correlation length. much larger than microscopic " lattice" scale " a"), and can be thought of as a CFT perturbed by a relevant perturbation. We show that for such ( 1+ 1) gapped Lorentz invariant field theories in infinite space, the low- lying entanglement spectrum obtained by tracing out, say, left half- infinite space, is precisely equal to the physical spectrum of the unperturbed gapless, i. e., conformal field theory defined on a finite interval of length L. = ln(xi/ a) with certain boundary conditions. In particular, the low- lying entanglement spectrum of the gapped theory is the finite- size spectrum of a boundary conformal field theory, and is always discrete and universal. Each relevant perturbation, and thus each gapped phase in proximity to the quantum phase transition, maps into a particular boundary condition. A similar property has been known to hold for Baxter's corner transfer matrices in a very special class of fine- tuned, namely, integrable off- critical lattice models, for the entire entanglement spectrum and independent of the scaling limit. In contrast, our result applies to completely general gapped Lorentz invariant theories in the scaling limit, without the requirement of integrability, for the low- lying entanglement spectrum. While the entanglement spectrum of the ground state of a gapped theory on a finite interval of length 2R with suitable boundary conditions, bipartitioned into two equal pieces, turns out to exhibit a crossover between the finite- size spectra of the same CFT with in general different boundary conditions as the system size R crosses the correlation length from the " critical regime" R << xi to the " gapped regime" R >> xi, the physical spectrum on a finite interval of length R with the same boundary conditions, on the other hand, is known to undergo a dramatic reorganization during the same crossover from being discrete to being continuous.2017-03-01T00:00:00Z