Bulletin of the American Physical Society
APS April Meeting 2011
Volume 56, Number 4
Saturday–Tuesday, April 30–May 3 2011; Anaheim, California
Session T13: Pushing the Boundariesof Quantum Mechanics and Gravity |
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Sponsoring Units: GPMFC Chair: Blayne Heckel, University of Washington Room: Royal EF |
Monday, May 2, 2011 3:30PM - 3:42PM |
T13.00001: Matter Waves and Clock Comparisons Michael Hohensee, Holger M\"uller The gravitational redshift and the universality of free fall have been known to be closely related to one another since the 1960s, when Schiff demonstrated that conservation of energy required any anomalies in one to be balanced by a matching violation of the other, and conjectured that this must be true in any consistent theory of gravity. It is thus no surprise that clock comparisons and matter wave interferometer tests of the effects of gravity set bounds on the same kinds of anomalous terms when considered at leading order in the context of the Standard Model Extension. Surprisingly, these seemingly distinct classes of experiment can be shown to be formally identical to one another in every way at leading order. We demonstrate this explicitly for the Mach-Zehnder matter-wave interferometer, and in the process correct a conceptual error common to many non-relativistic treatments of atom-photon interactions. This suggests that Schiff's conjecture might be proven trivially true if no test of the universality of free fall can be distinguished from a test of the gravitational redshift. Higher order deviations from general relativity are also considered. [Preview Abstract] |
Monday, May 2, 2011 3:42PM - 3:54PM |
T13.00002: Short-range force detection with optically-levitated microspheres Andrew Geraci, Scott Papp, John Kitching Optically levitated and cooled dielectric microspheres in ultra- high vacuum show great promise as resonant force detectors with an expected sub-attonewton sensitivity. Hence, they can be used to investigate Casimir forces or for testing non-Newtonian gravity [1]. We consider an experimental setup involving trapping a sub-wavelength silica microsphere in an optical cavity. The cavity is filled with two light fields to trap and cool the center of mass motion of the sphere, respectively. The sphere is trapped in an anti-node of the trapping light close to an end-mirror of the cavity. Casimir forces due to the end-mirror can be measured as a frequency shift of the oscillator, and non-Newtonian gravity-like forces can be measured by monitoring the displacement of the sphere as a mass is brought behind the cavity mirror. The technique we describe could potentially extend the search for non-Newtonian gravity by several orders of magnitude at the micrometer length scale. \\[4pt] [1] A.A.Geraci, S.B.Papp, and J.Kitching, Phys. Rev. Lett. 105, 101101 (2010). [Preview Abstract] |
Monday, May 2, 2011 3:54PM - 4:06PM |
T13.00003: Limits on possible new nucleon monopole-dipole interactions from measurements of the Spin Relaxation Rate of Polarized $^3$He Gas Changbo Fu, Mike Snow, Tom Gentile The possible existence of new interactions of nature with ranges of macroscopic scale and very weak couplings to matter has recently begun to attract more scientific attention. Many experiments search for such weakly-interacting sub-eV Particles (WISPs) [1]. Polarized $^{3}$He gas is an especially clean and convenient system to use to constrain possible new spin dependent interactions involving nucleons. We show that existing measurements of the transverse spin relaxation rate $\Gamma_{2}$ for polarized $^{3}$He gas can be used to set limits on the product $g_{s}g_{p}$ of scalar and pseudoscalar couplings for an interaction of ``monopole-dipole'' form for WISP masses in the $\mu$eV to meV range, corresponding to distances from centimeters to microns. We present limits from both a reanalysis of previous measurements of relaxation rate in $^{3}$He spin exchange cells and from data in a test experiment searching for a change in relaxation rate upon the motion of an unpolarized test mass. The outlook for more sensitive measurements using this technique will be discussed. References: [1] J. Jaeckel and A. Ringwald, Ann. Rev. Nucl. Part. Sci. {\bf 60}, 405 (2010). [Preview Abstract] |
Monday, May 2, 2011 4:06PM - 4:18PM |
T13.00004: Phenomenology of Lorentz-violating gravitational couplings Quentin Bailey Recent precision searches for miniscule violations of Lorentz invariance have been motivated in part by the possibility of uncovering signals from an underlying unified theory of physics. The effective field theory framework called the Standard-Model Extension (SME), which describes general Lorentz violation for known matter and fields, has been used in the analysis of many of these tests. In particular, the phenomenology of Lorentz-violating gravitational couplings in the SME has recently been explored in the literature and some measurements have already been published. I will discuss the status of this work, including recent solar system and Earth-based laboratory constraints on certain coefficients for Lorentz violation, as well as possibilities for future tests. [Preview Abstract] |
Monday, May 2, 2011 4:18PM - 4:30PM |
T13.00005: Classical Light Bending in the SME Framework Rhondale Tso, Quentin Bailey Classical light bending is investigated in weak gravitational fields based on the framework of the Lorentz-violating Standard- Model Extension (SME). We derive a modified deflection angle with anisotropic features that are characteristic of deviations from Lorentz Symmetry. In this talk, we also discuss methods to measure this deflection angle with current light-bending tests. [Preview Abstract] |
Monday, May 2, 2011 4:30PM - 4:42PM |
T13.00006: Lepton Decay in Hot and Dense Media Samina Masood We study the lepton decays in hot and dense media. For this purpose, we use renormalization scheme of QED and compute the radiative corrections to lepton decay rates in hot and dense background. The radiative corrections to these decay rates are calculated up to the two-loop level. We estimate the lepton decay rates as a function of temperature and density of the possibly existing media of the early universe and stellar cores. Some of the possible applications of these results in astrophysics and cosmology are also mentioned. [Preview Abstract] |
Monday, May 2, 2011 4:42PM - 4:54PM |
T13.00007: Classical relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated reference frame Domingo Louis-Martinez A classical (non-quantum-mechanical) relativistic ideal gas in thermodynamic equilibrium in a uniformly accelerated frame of reference is studied using Gibbs's microcanonical and grand canonical formulations of statistical mechanics. Using these methods explicit expressions for the particle, energy and entropy density distributions are obtained, which are found to be in agreement with the well known results of the relativistic formulation of Boltzmann's kinetic theory. Explicit expressions for the total entropy, total energy and rest mass of the gas are obtained. The position of the center of mass of the gas in equilibrium is found. The non-relativistic and ultrarelativistic approximations are also considered. The phase space volume of the system is calculated explicitly in the ultrarelativistic approximation. [Preview Abstract] |
Monday, May 2, 2011 4:54PM - 5:06PM |
T13.00008: There may be Fermi Energy levels in the hollow interiors of Nanotubes that would allow for a type of Quantum Richard Kriske There may be Fermi Energy levels that would allow for easy travel by Atoms, Molecules and Particles, in the hollow interior of Nanotubes. This may result in a Quantum Mechanical explaination of Capillary Action, and it may result in devices could take advantage of the idea that it takes no energy to rise in a Capillary tube, only in leaving it. This no-energy conjecture of Capillarity sounds very much like the idea that Electrons in obitals lose no Energy staying in orbit, only in changing orbits.It is this conjecture that may reveal that a Fermi Energy state is essentially in a weak orbital. This weak orbital could be exploited to store Anti-matter for instance. More profoundly it clearly shows how the Quantum Mechanical states meld smoothly into Classical Physics. It also reveals how extremely efficient Classical Machines could be constructed to take advantage of this spontaneous action. Say a tube could be designed to nudge electrons out of a weak obital in one place, sent down the tube (which is another weak orbital) and deposited in a weak orbital of another very distant Atom, apparently with little or perhaps no work being done, as long as the orbitals are the same energy. This may already exist in some Biological systems. Although more experimentation is needed, this would be the breakthrough that is needed to unify Classical and Quantum Mechanics. [Preview Abstract] |
Monday, May 2, 2011 5:06PM - 5:18PM |
T13.00009: Electrical conductance between multi-walled carbon nanotube and Cu Feng Gao, Jianmin Qu, Matthew Yao Vertical MWCNT interconnects have already been investigated for vias, or even for through-wafer 3D interconnects. Several studies have been done to understand the electrical conductance of MWCNT itself. The electrical conductance at a junction between MWCNT and metals has not been studied yet. Here we reported the intershell interaction effect on the electrical conductance at the Cu/MWCNT/Cu junctions by quantum mechanics calculations. Both end- and side-contacts between MWCNT and Cu electrodes were studied. In the end-contact junction, each individual CNT in the MWCNT acts as if it is a single wave CNT. The total conductance is almost the sum of the contributions from each individual nanotube. However, in the side-contact junction, the conductance between the outermost CNT and Cu electrode is dominant, whereas the intershell interaction leads to a reduction of the total electrical conductance. This is attributed to the enhanced localization of density of states in the vicinity of Fermi level by inner tube. [Preview Abstract] |
Monday, May 2, 2011 5:18PM - 5:30PM |
T13.00010: Coherence Lifetimes in the Charge Conserving Systems Due to the Thin Spectrum Evren Karakaya, Ozgur Mustecaplioglu We study the quantum coherence properties of the systems characterized by the damped harmonic oscillator using a toy model and thin spectrum model formalism. The decoherence time in the ground state, taken as a symmetry breaking state, is investigated. Apart from the number conserving systems, it is shown that the time that a system can stay quantum coherent exhibits a general characteristics in such symmetry breaking systems due to anomalous spectrum which was not considered before in the charge conserving systems [1,2]. Our results would be interest to the studies in the optical physics, in the condensed matter physics and even to the neurophysical model of the memory. References: [1] T.Birol, T. Dereli, O. E. Mustecaplioglu, L. You, Phys.Rev.A 76, 043616 (2007). [2] J. van Wezel, J. van den Brink, J. Zaanen, Phys. Rev. Lett. 94, 230401 (2005). [Preview Abstract] |
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