A5059789839- Atomic and Subatomic Physics Research
- Geology and Paleoclimatology Research
- Cold Atom Physics and Bose-Einstein Condensates
- Groundwater and Isotope Geochemistry
- Isotope Analysis in Ecology
- Advanced Frequency and Time Standards
- Nuclear Physics and Applications
- Cryospheric studies and observations
- Radioactive Decay and Measurement Techniques
- Atomic and Molecular Physics
- Radioactive contamination and transfer
- Quantum, superfluid, helium dynamics
- Methane Hydrates and Related Phenomena
- Groundwater flow and contamination studies
- Astro and Planetary Science
- Nuclear physics research studies
- Non-Destructive Testing Techniques
- Hydrocarbon exploration and reservoir analysis
- Quantum optics and atomic interactions
- Polar Research and Ecology
- Atmospheric and Environmental Gas Dynamics
- Scientific Measurement and Uncertainty Evaluation
- Mass Spectrometry Techniques and Applications
- Welding Techniques and Residual Stresses
- Dark Matter and Cosmic Phenomena
University of Science and Technology of China
2015-2025
Guilin University of Technology
2025
Hefei National Center for Physical Sciences at Nanoscale
2017-2024
Beijing Academy of Quantum Information Sciences
2022-2024
Chinese Academy of Sciences
2020-2024
Argonne National Laboratory
2011-2020
Goethe University Frankfurt
2020
University of Chicago
2008-2019
Fermi National Accelerator Laboratory
2007-2017
Syracuse University
2017
We demonstrate a robust method of stabilizing diode laser frequency to an atomic transition. This technique employs the Zeeman shift generate antisymmetric signal about Doppler-broadened resonance, and therefore offers large recapture range as well high stability. The 780-nm laser, stabilized such in Rb, drifted less than 0.5 MHz peak-peak (1 part 10(9)) 38 h. tunable lock can be constructed inexpensively, requires little power, rarely loses lock, extended other wavelengths by use different species.
We have produced and characterized an intense, slow, highly collimated atomic beam extracted from a standard vapor cell magneto-optical trap (MOT). The technique used is dramatically simpler than previous methods for producing very cold beams. created 0.6 mm diameter rubidium with continuous flux of $5\ifmmode\times\else\texttimes\fi{}{10}^{9}/\mathrm{s}$ pulsed 10 times greater. Its longitudinal velocity distribution centered at 14 m/s FWHM 2.7 m/s. Through efficient recycling process, 70%...
Measurements of 81Kr/Kr in deep groundwater from the Nubian Aquifer (Egypt) were performed by a new laser-based atom-counting method. 81Kr ages range \~2x10^5 to ~1x10^6 yr, correlate with 36Cl/Cl ratios, and are consistent lateral flow recharge area near Uweinat Uplift SW Egypt. Low delta-2H values 81Kr-dated reveal recurrent Atlantic moisture source during Pleistocene pluvial periods. These results indicate that method for dating old is robust such measurements can now be applied wide...
The root-mean-square (rms) nuclear charge radius of ^8He, the most neutron-rich all particle-stable nuclei, has been determined for first time to be 1.93(3) fm. In addition, rms ^6He was measured 2.068(11) fm, in excellent agreement with a previous result. significant reduction from ^8He is an indication change correlations excess neutrons and consistent neutron halo structure. experiment based on laser spectroscopy individual helium atoms cooled confined magneto-optical trap. Charge radii...
We have performed precision laser spectroscopy on individual 6He (t(1/2)=0.8 s) atoms confined and cooled in a magneto-optical trap, measured the isotope shift between 4He to be 43 194.772+/-0.056 MHz for 2(3)S1-3(3)P2 transition. Based this measurement atomic theory, nuclear charge radius of is determined first time method independent models 2.054+/-0.014 fm. The result compared with values predicted by number structure calculations tests their ability characterize loosely bound halo nucleus.
Background: Octupole-deformed nuclei, such as that of $^{225}\mathrm{Ra}$, are expected to amplify observable atomic electric dipole moments (EDMs) arise from time-reversal and parity-violating interactions in the nuclear medium. In 2015 we reported first ``proof-of-principle'' measurement $^{225}\mathrm{Ra}$ EDM.Purpose: This work reports on several experimental upgrades improve statistical sensitivity our EDM measurements by orders magnitude evaluates systematic effects contribute current...
Abstract Ultralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the of topological defects that could concentrate matter density into many distinct, compact spatial regions small compared with Galaxy but much larger than Earth. Here we report results search transient signals from domain walls by using global network optical magnetometers exotic (GNOME) physics searches. We data, consisting correlated...
TALDICE (TALos Dome Ice CorE) is a 1620 m deep ice core drilled at Talos Dome, an dome located the edge of East Antarctic Plateau in Ross Sea Sector. The Core Common Chronology (AICC2012) extended age scale until ∼150 ka (1438 depth) (Bazin et al., 2013), while no was available below 1438 depth. In this work we present new TALDICE-deep1 chronology using measurements δ18Oatm, δD and 81Kr as well inverse model IceChrono1. stops 1548 m, portion depth probably affected by mixing processes....
Among the four fundamental forces, only gravity does not couple to particle spins according general theory of relativity. We test this principle by searching for an anomalous scalar coupling between neutron spin and Earth's on ground. develop atomic gas comagnetometer measure ratio nuclear spin-precession frequencies Xe129 Xe131, search a change precision 10−9 as sensor is flipped in gravitational field. The null results set upper limit energy ground at 5.3×10−22 eV (95% confidence level),...
Laser manipulation of neutral atoms has been used to count individual krypton-85 and krypton-81 present in a natural krypton gas sample with isotopic abundances the range 10 −11 −13 , respectively. This method isotope trace analysis is free contamination from other isotopes elements can be applied several different tracers for wide applications. The demonstrated detection efficiency 1 × −7 . System improvements could increase by many orders magnitude.
The neutron-rich $^{6}\mathrm{He}$ and $^{8}\mathrm{He}$ isotopes exhibit an exotic nuclear structure that consists of a tightly bound $^{4}\mathrm{He}$-like core with additional neutrons orbiting at relatively large distance, forming halo. Recent experimental efforts have succeeded in laser trapping cooling these short-lived, rare helium atoms measured the atomic isotope shifts along $^{4}\mathrm{He}\mathrm{\text{\ensuremath{-}}}^{6}\mathrm{He}\mathrm{\text{\ensuremath{-}}}^{8}\mathrm{He}$...
Significance Past variations in Earth’s climate and atmospheric composition are recorded accumulating polar meteoric ice the air trapped within it. Ice outcrops provide accessible archives of old but difficult to date reliably. Here we demonstrate 81 Kr radiometric dating ice, allowing accurate up 1.5 million-year-old ice. The technique successfully identifies valuable from previous interglacial period at Taylor Glacier, Antarctica. Our method will enhance scientific value outcropping sites...
The magneto-optical trap (MOT) is an essential tool for collecting and preparing cold atoms with a wide range of applications. We demonstrate planar-integrated MOT by combining optical grating chip magnetic coil chip. flat simplifies the conventional six-beam configuration down to single laser beam, replaces anti-Helmholtz coils cylindrical geometry. Up ${10}^{6}$ ${}^{87}\mathrm{Rb}$ are trapped MOT, atom cloud being approximately $6\phantom{\rule{0.2em}{0ex}}\mathrm{mm}$ above surface....
41Ca (half-life = 99 ka) is a cosmogenic radionuclide that has long been proposed as promising dating tracer for geological and archaeological samples from Middle Late Pleistocene [1]. Calcium abundant residence time of 800 ka in the oceans, much longer than half-life 41Ca. This led to expectation uniform distribution 41Ca/Ca ratios oceans around globe. Ocean deposits acquire global seawater value upon initial formation. Since ocean are shielded cosmic rays by overlying seawater, no produced...
Paleoclimate reconstructions from ice core records can be hampered due to the lack of a reliable chronology, especially in deep ice, when stratigraphy is disturbed and conventional dating methods cannot applied. The noble gas radioisotopes 81Kr 39Ar these cases provide robust constraints as they yield absolute, radiometric ages. (t1/2=229 ka) covers time span 30-1500 ka, which relevant for polar cores, whereas (t1/2=268 a) with range 50-1600 suitable alpine glaciers. anthropogenic 85Kr...
The permanent electric dipole moment (EDM) of the $^{171}\mathrm{Yb}$ $(I=1/2)$ atom is measured with atoms held in an optical trap. By enabling a cycling transition that simultaneously spin-selective and spin-preserving, quantum nondemolition measurement spin-detection efficiency 50% realized. A systematic effect due to parity mixing induced by static $E$ field observed, suppressed averaging between measurements traps opposite directions. coherent spin precession time found be much longer...
Abstract. The EPICA (European Project for Ice Coring in Antarctica) Dome C (EDC) ice core drilling East Antarctica reaches a depth of 3260 m. reference EDC chronology, the AICC2012 (Antarctic Core Chronology 2012), provides an age vs. relationship covering last 800 kyr (thousands years), with absolute uncertainty rising up to 8000 years at bottom core. origins this relatively large are twofold: (1) δ18Oatm, δO2/N2 and total air content (TAC) records poorly resolved show gaps over kyr, (2)...
85Kr (t1/2=10.7 a), 39Ar (t1/2=268 a) and 81Kr (t1/2=229 ka) are valuable isotopes for radiometric dating of groundwater, especially due to their gaseous properties chemical inertness. Together with 14C, these radioisotopes cover the age range from present back 1.5 million years. Due extremely low environmental abundances 10-17…10-11, corresponding only a few thousand atoms per kilogram water or ice, detection is very challenging. In recent two decades, laser-based method Atom Trap...
Skytrain Ice Rise is a separate ice flow centre at the inland edge of Ronne Shelf, on periphery West Antarctic Sheet. An core drilled through to base 651 m was dated as far 126 ka before present, which found 627 depth. This has been used so investigate climate and sheet stability Holocene last interglacial. Here we between Three methods for dating old have applied samples within this depth range. Analysis using ATTA method 81Kr, with half-life 229 kyr, carried out three 635 648 m, well one...