Metastable Helium: A New Determination of the Longest Atomic Excited-State Lifetime

Hodgman, Sean; Dall, Robert; Byron, Lesa; Baldwin, K. G. H.; Buckman, Stephen; Truscott, A. G.

doi:10.1103/physrevlett.103.053002

Cited by 104 publications

(69 citation statements)

References 19 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In our experiments, we guide He* atoms that are in a long-lived metastable state 21 possessing ~20 eV of internal energy and allowing single atom detection. A single 1,550-nm focused laser beam provides the guiding potential, which minimizes spontaneous scattering of photons because of its large red detuning from the relevant He* transition (1,083 nm).…”

Section: Experiments Overviewmentioning

confidence: 99%

Observation of atomic speckle and Hanbury Brown–Twiss correlations in guided matter waves

et al. 2011

View full text Add to dashboard Cite

speckle patterns produced by multiple independent light sources are a manifestation of the coherence of the light field. second-order correlations exhibited in phenomena such as photon bunching, termed the Hanbury Brown-Twiss effect, are a measure of quantum coherence. Here we observe for the first time atomic speckle produced by atoms transmitted through an optical waveguide, and link this to second-order correlations of the atomic arrival times. We show that multimode matter-wave guiding, which is directly analogous to multimode light guiding in optical fibres, produces a speckled transverse intensity pattern and atom bunching, whereas single-mode guiding of atoms that are output-coupled from a Bose-Einstein condensate yields a smooth intensity profile and a second-order correlation value of unity. Both first-and secondorder coherence are important for applications requiring a fully coherent atomic source, such as squeezed-atom interferometry.

show abstract

Section: Experiments Overviewmentioning

confidence: 99%

Observation of atomic speckle and Hanbury Brown–Twiss correlations in guided matter waves

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Earlier measurements using an electric discharge in a highly perturbed environment yielded error bars of at least 30% (Moos and Woodworth, 1973;Woodworth and Moos, 1975), compared with the most recent experimental uncertainty of 6.5% (Hodgman et al, 2009b). It should be noted that the recent experiment covered a range of more than six orders of magnitude in XUV count rates.…”

Section: Spectroscopic Measurements Of Atomic Properties a Metasmentioning

confidence: 99%

“…Summarizing, experiment and theory are in good agreement for all 3 decay rates at a level of accuracy of ∼ 5%. The results are listed in Table II. The value determined for the He metastable lifetime -7870 (510)s (Hodgman et al, 2009b) -is the longest of any excited neutral atomic species yet measured. Once again, this experimental determination anchors the isoelectronic sequence for the helium-like metastable lifetime at low Z and again confirms the previous three most consistent theories (Drake, 1971;Johnson and Plante, 1995;Lach and Pachucki, 2001).…”

Section: Spectroscopic Measurements Of Atomic Properties a Metasmentioning

confidence: 99%

Cold and trapped metastable noble gases

et al. 2012

View full text Add to dashboard Cite

We review experimental work on cold, trapped metastable noble gases. We emphasize the aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general. These aspects include detection techniques and collision processes unique to metastable atoms. We describe several experiments exploiting these unique features in fields including atom optics and statistical physics. We also discuss precision measurements on these atoms including fine structure splittings, isotope shifts, and atomic lifetimes.

show abstract

“…The possibility to accurately calculate level energies and wavefunctions has allowed confrontation with several other experimental results. Radiative lifetimes of the 2 3 S 1 and 2 1 P 1 states have been measured in cold clouds of helium atoms initially prepared in the metastable 2 3 S 1 state of 4 He [10,11], showing good agreement with theory. Also molecular potentials for two metastable helium atoms can be calculated very accurately in some cases.…”

Section: Introductionmentioning

confidence: 74%

Ultracold metastable helium: Ramsey fringes and atom interferometry

et al. 2016

View full text Add to dashboard Cite

equation cannot be solved exactly. Level energies are therefore more difficult to calculate than for atomic hydrogen showing a more stringent test of atomic physics theory. Calculations of level energies and transition frequencies have pushed our understanding of atomic physics since the twenties of last century. A major breakthrough occurred in the nineties with the advent of variational calculations in a double basis set in correlated form for the electrons, adding relativistic and quantum electrodynamics (QED) terms in orders of the fine structure constant α and the reduced electron to helium mass ratio µ/M He [1, 2]. As nonrelativistic calculations can now be performed to virtually arbitrary precision, measurements of level energies nowadays are sensitive to QED and nuclear size effects. As these effects are strongest for S-states and small principle quantum number n, the n 1,3 S states are theoretically the most promising to test QED. In particular the n = 2 states are important for high-resolution spectroscopy as these also show long lifetimes, 7800 s for the 2 3 S 1 state and 20 ms for the 2 1 S 0 state (natural linewidth 8 Hz), while the 2 3 P state has, for an allowed electric dipole transition, a relatively long lifetime of 98 ns (natural linewidth 1.6 MHz). A helium level scheme is shown in Fig. 1.Transition frequencies in helium can nowadays be measured more accurately than calculated, where the theoretical limitation is in the calculation of high-order QED terms. This hampers extraction of the charge radius of the helium nucleus (the alpha-particle for 4 He and the helion for 3 He ) from transition frequencies with an accuracy that can compete with other experiments. However, in calculating transition isotope shifts between 4 He and 3 He, QED terms cancel to a large extent, allowing very accurate extraction of the difference in the (squared) nuclear charge radii of the alpha-particle and the helion. This is particularly interesting in relation to the proton size puzzle [3][4][5]. To help solving Abstract We report on interference studies in the internal and external degrees of freedom of metastable triplet helium atoms trapped near quantum degeneracy in a 1.5 µm optical dipole trap. Applying a single π/2 rf pulse we demonstrate that 50% of the atoms initially in the m = +1 state can be transferred to the magnetic field insensitive m = 0 state. Two π/2 pulses with varying time delay allow a Ramsey-type measurement of the Zeeman shift for a high precision measurement of the 2 3 S 1 -2 1 S 0 transition frequency. We show that this method also allows strong suppression of mean-field effects on the measurement of the Zeeman shift, which is necessary to reach the accuracy goal of 0.1 kHz on the absolute transition frequencies. Theoretically the feasibility of using metastable triplet helium atoms in the m = 0 state for atom interferometry is studied demonstrating favorable conditions, compared to the alkali atoms that are used traditionally, for a non-QED determination of the fine structure constant.

show abstract

Metastable Helium: A New Determination of the Longest Atomic Excited-State Lifetime

Cited by 104 publications

References 19 publications

Observation of atomic speckle and Hanbury Brown–Twiss correlations in guided matter waves

Observation of atomic speckle and Hanbury Brown–Twiss correlations in guided matter waves

Cold and trapped metastable noble gases

Ultracold metastable helium: Ramsey fringes and atom interferometry

Contact Info

Product

Resources

About