331 research outputs found
High Efficiency Positron Accumulation for High-Precision Measurements
Positrons are accumulated within a Penning trap designed to make more precise
measurements of the positron and electron magnetic moments. The retractable
radioactive source used is weak enough to require no license for handling
radioactive material and the radiation dosage one meter from the source gives
an exposure several times smaller than the average radiation dose on the
earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K
superconducting solenoid that produces a 6 tesla magnetic trapping field with a
direct mechanical coupling.Comment: 7 pages, 9 figure
Optimized Planar Penning Traps for Quantum Information Studies
A one-electron qubit would offer a new option for quantum information
science, including the possibility of extremely long coherence times.
One-quantum cyclotron transitions and spin flips have been observed for a
single electron in a cylindrical Penning trap. However, an electron suspended
in a planar Penning trap is a more promising building block for the array of
coupled qubits needed for quantum information studies. The optimized design
configurations identified here promise to make it possible to realize the
elusive goal of one trapped electron in a planar Penning trap for the first
time - a substantial step toward a one-electron qubit
Simple self-calibrating polarimeter for measuring the Stokes parameters of light
A simple, self-calibrating, rotating-waveplate polarimeter is largely
insensitive to light intensity fluctuations and is shown to be useful for
determining the Stokes parameters of light. This study shows how to minimize
the in situ self-calibration time, the measurement time and the measurement
uncertainty. The suggested methods are applied to measurements of spatial
variations in the linear and circular polarizations of laser light passing
through glass plates with a laser intensity dependent birefringence. These are
crucial measurements for the ACME electron electric dipole measurements,
requiring accuracies in circular and linear polarization fraction of about 0.1%
and 0.4%, with laser intensities up to 100 incident into the
polarimeter
First Production and Detection of Cold Antihydrogen Atoms
The ATHENA experiment recently produced the first atoms of cold antihydrogen.
This paper gives a brief review of how this was achieved.Comment: Invited talk at Int. Conf. on Low Energy Antiprotons 2003 (LEAP03),
to be published in NIM
Towards electron-electron entanglement in Penning traps
Entanglement of isolated elementary particles other than photons has not yet been achieved. We show how building blocks demonstrated with one trapped electron might be used to make a model system and method for entangling two electrons. Applications are then considered, including two-qubit gates and more precise quantum metrology protocols
Dark energy, antimatter gravity and geometry of the Universe
This article is based on two hypotheses. The first one is the existence of
the gravitational repulsion between particles and antiparticles. Consequently,
virtual particle-antiparticle pairs in the quantum vacuum may be considered as
gravitational dipoles. The second hypothesis is that the Universe has geometry
of a four-dimensional hyper-spherical shell with thickness equal to the Compton
wavelength of a pion, which is a simple generalization of the usual geometry of
a 3-hypersphere. It is striking that these two hypotheses lead to a simple
relation for the gravitational mass density of the vacuum, which is in very
good agreement with the observed dark energy density
Electron-radiation interaction in a Penning trap: beyond the dipole approximation
We investigate the physics of a single trapped electron interacting with a
radiation field without the dipole approximation. This gives new physical
insights in the so-called geonium theory.Comment: 12 pages, RevTeX, 6 figures, Approved for publication in Phys. Rev.
Shot-noise-limited spin measurements in a pulsed molecular beam
Heavy diatomic molecules have been identified as good candidates for use in
electron electric dipole moment (eEDM) searches. Suitable molecular species can
be produced in pulsed beams, but with a total flux and/or temporal evolution
that varies significantly from pulse to pulse. These variations can degrade the
experimental sensitivity to changes in spin precession phase of an electri-
cally polarized state, which is the observable of interest for an eEDM
measurement. We present two methods for measurement of the phase that provide
immunity to beam temporal variations, and make it possible to reach
shot-noise-limited sensitivity. Each method employs rapid projection of the
spin state onto both components of an orthonormal basis. We demonstrate both
methods using the eEDM-sensitive H state of thorium monoxide (ThO), and use one
of them to measure the magnetic moment of this state with increased accuracy
relative to previous determinations.Comment: 12 pages, 6 figure
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