34 research outputs found
Transverse laser cooling of a thermal atomic beam of dysprosium
A thermal atomic beam of dysprosium (Dy) atoms is cooled using the
transition at 421 nm. The cooling is
done via a standing light wave orthogonal to the atomic beam. Efficient
transverse cooling to the Doppler limit is demonstrated for all observable
isotopes of dysprosium. Branching ratios to metastable states are demonstrated
to be . A scheme for enhancement of the
nonzero-nuclear-spin-isotope cooling, as well as a method for direct
identification of possible trap states, is proposed.Comment: 5 pages, 4 figures v2: 7 pages, 7 figure
Search for the effect of massive bodies on atomic spectra and constraints on Yukawa-type interactions of scalar particles
We propose a new method to search for hypothetical scalar particles that have
feeble interactions with Standard-Model particles. In the presence of massive
bodies, these interactions produce a non-zero Yukawa-type scalar-field
magnitude. Using radio-frequency spectroscopy data of atomic dysprosium, as
well as atomic clock spectroscopy data, we constrain the Yukawa-type
interactions of a scalar field with the photon, electron, and nucleons for a
range of scalar-particle masses corresponding to length scales cm. In
the limit as the scalar-particle mass , our derived limits on the
Yukawa-type interaction parameters are: GeV, GeV, and GeV. Our measurements also constrain combinations of
interaction parameters, which cannot otherwise be probed with traditional
anomalous-force measurements. We suggest further measurements to improve on the
current level of sensitivity.Comment: 7 pages, 2 figure
Dynamic polarizabilities and magic wavelengths for dysprosium
We theoretically study dynamic scalar polarizabilities of the ground and
select long-lived excited states of dysprosium, a highly magnetic atom recently
laser cooled and trapped. We demonstrate that there are a set of magic
wavelengths of the unpoarized lattice laser field for each pair of states which
includes the ground state and one of these excited states. At these
wavelengths, the energy shift due to laser field is the same for both states,
which can be useful for resolved sideband cooling on narrow transitions and
precision spectroscopy. We present an analytical formula which, near
resonances, allows for the determination of approximate values of the magic
wavelengths without calculating the dynamic polarizabilities of the excited
states.Comment: 6 papers, 3 figure
Limit on the Temporal Variation of the Fine-Structure Constant Using Atomic Dysprosium
Over a period of eight months, we have monitored transition frequencies
between nearly degenerate, opposite-parity levels in two isotopes of atomic
dysprosium (Dy). These transition frequencies are highly sensitive to temporal
variation of the fine-structure constant () due to relativistic
corrections of large and opposite sign for the opposite-parity levels. In this
unique system, in contrast to atomic-clock comparisons, the difference of the
electronic energies of the opposite-parity levels can be monitored directly
utilizing a radio-frequency (rf) electric-dipole transition between them. Our
measurements show that the frequency variation of the 3.1-MHz transition in
Dy and the 235-MHz transition in Dy are 9.06.7 Hz/yr and
-0.66.5 Hz/yr, respectively. These results provide a value for the rate of
fractional variation of of yr (1
) without any assumptions on the constancy of other fundamental
constants, indicating absence of significant variation at the present level of
sensitivity.Comment: 4 pages, 2 figure
Limiting P-odd interactions of cosmic fields with electrons, protons and neutrons
We propose methods for extracting limits on the strength of P-odd
interactions of pseudoscalar and pseudovector cosmic fields with electrons,
protons and neutrons. Candidates for such fields are dark matter (including
axions) and dark energy, as well as several more exotic sources described by
standard-model extensions. Calculations of parity nonconserving amplitudes and
atomic electric dipole moments induced by these fields are performed for H, Li,
Na, K, Rb, Cs, Ba+, Tl, Dy, Fr, and Ra+. From these calculations and existing
measurements in Dy, Cs and Tl, we constrain the interaction strengths of the
parity-violating static pseudovector cosmic field to be 7*10^(-15) GeV with an
electron, and 3*10^(-8) GeV with a proton.Comment: 6 pages, 1 figur
Parity-violating interactions of cosmic fields with atoms, molecules, and nuclei: Concepts and calculations for laboratory searches and extracting limits
We propose methods and present calculations that can be used to search for
evidence of cosmic fields by investigating the parity-violating effects,
including parity nonconservation amplitudes and electric dipole moments, that
they induce in atoms. The results are used to constrain important fundamental
parameters describing the strength of the interaction of various cosmic fields
with electrons, protons, and neutrons. Candidates for such fields are dark
matter (including axions) and dark energy, as well as several more exotic
sources described by standard-model extensions. Existing parity nonconservation
experiments in Cs, Dy, Yb, and Tl are combined with our calculations to
directly place limits on the interaction strength between the temporal
component, b_0, of a static pseudovector cosmic field and the atomic electrons,
with the most stringent limit of |b_0^e| < 7*10^(-15) GeV, in the laboratory
frame of reference, coming from Dy. From a measurement of the nuclear anapole
moment of Cs, and a limit on its value for Tl, we also extract limits on the
interaction strength between the temporal component of this cosmic field, as
well as a related tensor cosmic-field component d_00, with protons and
neutrons. The most stringent limits of |b_0^p| < 4*10^(-8) GeV and |d_00^p| <
5*10^(-8) for protons, and |b_0^n| < 2*10^(-7) GeV and |d_00^n| < 2*10^(-7) for
neutrons (in the laboratory frame) come from the results using Cs. Axions may
induce oscillating P- and T-violating effects in atoms and molecules through
the generation of oscillating nuclear magnetic quadrupole and Schiff moments,
which arise from P- and T-odd intranuclear forces and from the electric dipole
moments of constituent nucleons. Nuclear-spin-independent parity
nonconservation effects may be enhanced in diatomic molecules possessing close
pairs of opposite-parity levels in the presence of time-dependent interactions.Comment: 18 pages, 3 figures, 4 tables, Editor's Suggestio
Cavity-enhanced room-temperature magnetometry using absorption by nitrogen-vacancy centers in diamond
We demonstrate a cavity-enhanced room-temperature magnetic field sensor based
on nitrogen-vacancy centers in diamond. Magnetic resonance is detected using
absorption of light resonant with the 1042 nm spin-singlet transition. The
diamond is placed in an external optical cavity to enhance the absorption, and
significant absorption is observed even at room temperature. We demonstrate a
magnetic field sensitivity of 2.5 nT/sqrt(Hz), and project a photon
shot-noise-limited sensitivity of 70 pT/sqrt(Hz) for a few mW of infrared
light, and a quantum projection-noise-limited sensitivity of 250 fT/sqrt(Hz)
for the sensing volume of 90 um x 90 um 200 um.Comment: main text 5 pages, supplementary material 3 page
Investigation of the Gravitational Potential Dependence of the Fine-Structure Constant Using Atomic Dysprosium
Radio-frequency E1 transitions between nearly degenerate, opposite parity
levels of atomic dysprosium were monitored over an eight month period to search
for a variation in the fine-structure constant. During this time period, data
were taken at different points in the gravitational potential of the Sun. The
data are fitted to the variation in the gravitational potential yielding a
value of for the fit parameter . This
value gives the current best laboratory limit. In addition, our value of
combined with other experimental constraints is used to extract
the first limits on k_e and k_q. These coefficients characterize the variation
of m_e/m_p and m_q/m_p in a changing gravitational potential, where m_e, m_p,
and m_q are electron, proton, and quark masses. The results are and .Comment: 6 pages, 3 figure