Atomic Temperature Research Articles

In situ calibrated angle between the quantization axis and the propagating direction of the light field for trapping neutral atoms

The recently developed magic-intensity trapping technique of neutral atoms efficiently mitigates the detrimental effect of light shifts on atomic qubits and substantially enhances the coherence time. This technique relies on applying a bias magnetic field precisely parallel to the wave vector of a circularly polarized trapping laser field. However, due to the presence of the vector light shift experienced by the trapped atoms, it is challenging to precisely define a parallel magnetic field, especially at a low bias magnetic field strength, for the magic-intensity trapping of 85Rb qubits. In this work, we present a method to calibrate the angle between the bias magnetic field and the trapping laser field with the compensating magnetic fields in the other two directions orthogonal to the bias magnetic field direction. Experimentally, with a constant-depth trap and a fixed bias magnetic field, we measure the respective resonant frequencies of the atomic qubits in a linearly polarized trap and a circularly polarized one via the conventional microwave Rabi spectra with different compensating magnetic fields and obtain the corresponding total magnetic fields via the respective resonant frequencies using the Breit–Rabi formula. With known total magnetic fields, the angle is a function of the other two compensating magnetic fields. Finally, the projection value of the angle on either of the directions orthogonal to the bias magnetic field direction can be reduced to 0(4)° by applying specific compensating magnetic fields. The measurement error is mainly attributed to the fluctuation of atomic temperature. Moreover, it also demonstrates that, even for a small angle, the effect is strong enough to cause large decoherence of Rabi oscillation in a magic-intensity trap. Although the compensation method demonstrated here is explored for the magic-intensity trapping technique, it can be applied to a variety of similar precision measurements with trapped neutral atoms.

Method for estimating elastic modulus of doped semiconductors by using ab initio calculations—Doping effect on Young’s modulus of silicon crystal

A novel method for estimating the elastic modulus of doped semiconductors using ab initio calculation is demonstrated for a Si crystal. The elastic modulus of various materials basically depends on lattice constants on which dependence is shown by ab initio calculation and actually depends on the temperature, species, and concentration of doped atoms. This paper focuses on the dependences of species and concentrations of doped atoms at room temperature and shows the simplest procedure within Vegard’s law for estimating the elastic modulus of doped semiconductors.

Optimal lattice depth on lifetime of D-band ultracold atoms in a triangular optical lattice.

Ultracold atoms in optical lattices are a flexible and effective platform for quantum precision measurement, and the lifetime of high-band atoms is an essential parameter for the performance of quantum sensors. In this work, we investigate the relationship between the lattice depth and the lifetime of D-band atoms in a triangular optical lattice and show that there is an optimal lattice depth for the maximum lifetime. After loading the Bose-Einstein condensate into D band of optical lattice by shortcut method, we observe the atomic distribution in quasi-momentum space for the different evolution time, and measure the atomic lifetime at D band with different lattice depths. The lifetime is maximized at an optimal lattice depth, where the overlaps between the wave function of D band and other bands (mainly S band) are minimized. Additionally, we discuss the influence of atomic temperature on lifetime. These experimental results are in agreement with our numerical simulations. This work paves the way to improve coherence properties of optical lattices, and contributes to the implications for the development of quantum precision measurement, quantum communication, and quantum computing.

Optimizing Rydberg Gates for Logical-Qubit Performance

Robust gate sequences are widely used to reduce the sensitivity of gate operations to experimental imperfections. Typically, the optimization minimizes the average gate error, however, recent work in quantum error correction has demonstrated that the performance of encoded logical qubits is sensitive to not only the average error rate, but also the type of errors that occur. Here, we present a family of Rydberg blockade gates for neutral atom qubits that are robust against two common, major imperfections: intensity inhomogeneity and Doppler shifts. These gates outperform existing gates for moderate or large imperfections. We also consider the logical performance of these gates in the context of an erasure-biased qubit based on metastable $~^{171}$Yb. In this case, we observe that the robust gates outperform existing gates for even very small values of the imperfections, because they maintain the native large bias towards erasure errors for these qubits. These results significantly reduce the laser stability and atomic temperature requirements to achieve fault-tolerant quantum computing with neutral atoms. The approach of optimizing gates for logical qubit performance may be applied to other qubit platforms.

New lasers for climate research

PhotonicsViewsVolume 20, Issue 3 p. 96-96 PreviewsFree Access New lasers for climate research How do you measure the temperature of individual atoms at an altitude of ninety kilometers? First published: 20 June 2023 https://doi.org/10.1002/phvs.202370322AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume20, Issue3June/July 2023Pages 96-96 RelatedInformation

Gravitation-induced temperature of single atoms on atomic and cosmological scales

The experimental findings on the rate of transfer of a single Xe atom from the sample surface towards the tip in the low temperature STM, induced by voltage pulses, are understood by assuming a vibrational temperature for a single Xe atom. But temperature is introduced in standard quantum physics as a parameter in the Boltzmann distribution of a statistical ensemble consisting of large number of non-interacting exact copies of the dynamical system under investigation. This represents a problem, if the system under investigation is to be described by a single pure quantum state being a solution of Schrödinger’s equation. In the framework of a quantum field theory based on Einstein-Hilbert action in high dimensions (EHHD) we demonstrate that temperature for a single atom emerges if the atom is beabled in a warp resonance due to entanglement with local gravitons (gravonons), living in high spacetime dimensions (11D). Desorbing Xe atom in a limbo state in the tunnel gap, due to destruction of the beable via inelastic tunnelling, is in Boltzmann distribution over plane waves {| k〉} since the squared overlap of the warp resonance with free plane wave states varies like exp(–Ek/kBTvib ) where Ek is the energy of the free particle state and Tvib is the vibrational temperature of Xe calculated from the shape and the extension of the warp resonance. The nature of the warp resonance varies with the tip-sample voltage (becoming more contracted at higher tunnelling currents, as the tip approaches the sample) and raises its energy to higher values. More contracted warps at higher tunnelling currents imply stronger overlap with free states of higher energy, described by Boltzmann factors of higher temperature. The mechanism generating single atom temperature generalizes to other dynamical processes where temperature is completely determined by the nature of the warp resonance in the beables. For homogeneous and isotropic systems this implies a universal value of the temperature everywhere in the system. With these considerations the mechanism is also applied to intergalactic hydrogen-atom clusters, where it explains the observed temperature of the CMB radiation and the absence of the horizon problem.

Fabrication of Bilayer Stacked Antiferroelectric/ Ferroelectric HfxZr1-xO2 FeRAM and FeFET With Improved Leakage Current and Robust Reliability by Modifying Atomic Layer Deposition Temperatures

We fabricated FeRAM and FeFET with a bilayer Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (HZO), which comprises 5-nm-thick antiferroelectric HZO and 5-nm-thick ferroelectric HZO. Higher orthorhombic phase and large grain size were shown in grazing-incidence x-ray diffraction and TEM results, respectively. By using low ALD temperature, the leakage current (< 3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> under ±2V), gate control ability, the memory window (> 1.5V) and the endurance (> 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> cycles) have been improved. These results suggest that a low atomic layer deposition temperature is a promising process for use in non-volatile memory devices.

Internal Dynamic Temperature Measurement of Alkali Metal Vapor Cell by Kalman Filter

Measuring the internal dynamic temperature of alkali metal vapor cells is crucial for enhancing the performance of numerous atomic devices. However, conventional methods of measuring the internal dynamic temperature of the cell are prone to errors. To obtain a more accurate internal dynamic temperature of the alkali metal vapor cell, a temperature measuring method based on the data fusion of the Kalman filter has been proposed. This method combines the indirect temperature measurement signal from a resistance temperature detector with the atomic absorption spectrometric temperature measurement signal. This provides a high-accuracy set of internal dynamic temperatures in the cell. The atomic vapor density calculated from the final fusion results is 37% average lower than that measured by external wall temperature measurements, which is in line with the conclusions reached in many previous studies. This study is highly beneficial to measure the temperature of alkali metal vapor cells.

Climatology of 557.7 nm Emission Layer Parameters over South-East Siberia, Observations and Model Data

The paper deals with long-term means of 557.7 nm atomic oxygen airglow intensity (OI) and air temperature within the mesopause over the southern regions of East Siberia. Data on temperature and emission parameters were obtained with a SABER radiometer, KEO Scientific “Arinae” Fabry–Pérot interferometer, SATI spectrometer and NRLMSIS model over the Tory Geophysical Observatory (52° N, 103° E). Annual variations of 557.7 nm emission intensity and temperature obtained in observations differ from model approximations. Potential reasons for the discrepancies revealed are discussed.

Synthesis, characterization, and quantum chemistry local chemical reactivity description of new phosphorylated derivatives of piperazine

We report a fast, safe, and efficient procedure for the synthesis of phosphorylated derivatives of piperazines through a multicomponent reaction (MCR) strategy. Our key reagents were the piperazines 1-(2-methoxyphenyl) piperazine and 3-(4- (2-methoxyphenyl) piperazin-1-yl) propan-1-amine which reacted with five different phosphorous chlorides. A total of ten new derivatives were obtained, all confirmed by NMR spectroscopy (1H, 13C, and 31P) and mass spectrometry. Then, the reactivity profile of our new compounds was characterized through the new theoretical framework of the Local Electronic Temperature of Atoms in Molecules (LT-AIMs), from which we identified the most reactive sites of each of our derivatives. Furthermore, some of the quantities defined within this context were used to reproduce trends observed in our NMR records. A brief discussion about the advantages of performing a combined experimental and theoretical chemical characterization of recently synthesized compounds is also presented, particularly for those compounds with potential therapeutic features.

TALIF at H− ion sources for the determination of the density and EDF of atomic hydrogen

The production of H− ions in negative ion sources relevant for particle accelerator facilities and neutral beam injection systems is based predominantly on the surface conversion of H atoms at a low work function surface covered with caesium (the plasma grid (PG)). Therefore, the H atom density n H and energy distribution function (EDF) close to the PG determine the amount of surface produced H− ions. As a direct method for the density and EDF determination, two-photon absorption laser induced fluorescence (TALIF) on H atoms was implemented at the ion source of the teststand BATMAN Upgrade (BUG) being the first time that this was accomplished at an H− ion source. Several challenges had to be overcome concerning the application of the diagnostic at the complex facility and the evaluation of the fluorescence signals against a bright H background. The observed line profiles suggest a Maxwellian EDF with an H atom temperature of K. The presence of highly energetic H atoms (measured by optical emission spectroscopy, (OES)) could not be resolved by the TALIF system due to the insufficient signal-to-noise ratio. Atomic densities were measured for H2 and D2 plasmas for varying ion source parameters at BUG resulting in values between m−3 and m−3 for hydrogen. For the operation with deuterium, higher atomic densities are observed for similar ion source parameters which agree well with the previous results obtained with OES.

Determinations of Cadmium, Tin, Copper, Iron and Zinc in Food Samples by Electrothermal and Flame Atomic Absorption Spectrometries

Cadmium, tin, iron, copper, and zinc in tea, rice, and liver samples, and standard reference materials (IRMM 804 Rice Flour, GBW 10010 Rice, Bovine Liver1577c and GBW 07605 Tea Leaves) were determined by using electrothermal and flame atomic absorption spectrometries. Cd and Sn in sample solutions were determined with electrothermal atomic absorption spectrometry by using palladium (Pd) as a matrix modifier. Pyrolysis and atomization temperatures and pyrolysis times of Cd and Sn in sample solutions were optimized in the absence or presence of Pd. Pyrolysis temperatures of Cd and Sn found in the presence of Pd were 800°C and 1200°C, respectively. Iron, Cu, and Zn in samples were determined by flame atomic absorption spectrometry. The accuracy and precision of the method were validated by determining elements in standard reference materials. Limits of detection for Sn, Cd, Fe, Cu, and Zn were found as 0.66, 0.26, 2.0, 1.9, and 1.2 μg/L, respectively. Concentrations of elements found in samples were compared with maximum values reported by World Health Organization (WHO) and other studies.

Autler–Townes splitting in the trap-loss fluorescence spectroscopy due to single-step direct Rydberg excitation of cesium cold atomic ensemble

We experimentally investigate trap-loss spectra of the cesium 6S1/2(F = 4) → 71P3/2 Rydberg transition by combining the cesium atomic magneto-optical trap with the narrow-linewidth, continuously tunable 318.6 nm ultraviolet laser. Specifically, the atoms in the magneto-optical trap are excited to the Rydberg state due to the ultraviolet laser single-step Rydberg excitation, which leads to the reduction of atomic fluorescence. Based on the trap-loss spectroscopy technology, the Autler–Townes (AT) splitting due to a strong cooling laser is observed, and the parameter dependence of the AT splitting interval of trap-loss spectroscopy is investigated. The effective temperature of cold atoms is measured by using simplified time-of-flight fluorescence imaging. In addition, closed-loop feedback power stabilization of 318.6 nm ultraviolet laser is carried out. This lays the foundation for further experimental research related to the Rydberg atoms using ultraviolet lasers, which is of great significance for the development of quantum computing and quantum information.

Determination of Cr, Se, Ge, and V in Hypothyroidism Patients by Using Graphite Furnace Atomic Absorption Spectrometry and mixture matrix modification

A simple, accurate and rapid method was developed for routine determination of trace elements in blood serum. The method based on the direct determination for Cr, Se, Ge, and V in hypothyroidism patients before therapy. By using atomic absorption spectrometry with graphite surface coated and uncoated pyrolysis GF-AAS, and a mixture of palladium nitrate and magnesium nitrate as the matrix modifier, with deuterium background correction and no sample pretreatment except dilution was necessary. This permitted direct determination hence the risk of sample contamination was reduced. Further, the use of graphite surface-coated GF-AAS decreased the ashing and atomization temperatures of Cr, Ge, and V to values that were lesser than the corresponding values obtained using uncoated pyrolysis GF-AAS, by 100°C; in case of Se, the atomization temperature decreased to a value that was 200°C lesser than that obtained using uncoated pyrolysis GF-AAS.&#x0D; A mixture of (3µL) palladium nitrate, and (2µL) magnesium nitrate was successfully applied to improve the sensitivity, reproducibility, recovery, limit of detection and the accuracy of the measurements. The correlation coefficients of the calibration curves of Cr, Se, Ge, and V were found to be (0.9999, 0.9999, 0.9995 and 0.9999) respectively, the relative standard deviation of the measurements for Cr, Se, Ge and V were (0.027, 0.075, 0.054 and 0.068) respectively. The statistical analysis of the acquired data showed acceptable accuracy. The analyses thus performed indicated that the levels of serum trace elements Cr, Se, Ge, and V in hypothyroidism patients were lower than those in the control group.

Technical characteristics and coating formation mechanism of gilded silver products unearthed from the Consort Tomb of Emperor Shengzong of the Liao dynasty

Compared with other gold plating processes, mercury gilding was widely used in ancient China due to the less consumption of gold and excellent adhesion between the gold layer and substrate. Herein, the comprehensive analyses of the silver crown and boots unearthed from the Consort Tombs of Emperor Shengzong (圣宗萧贵妃) of the Liao (辽) Dynasty reveal the surface composition and structural characteristics and also the unique multilayered structure and cross-sectional compositional distribution of the gold layer. First, the existence of mercury on the golden surface of cultural relics, as well as the unique porous structure and granular surface morphology, indicate that the artifacts were probably processed using mercury gilding. In addition, the intermetallic compound, i.e., Au5Hg, in the gold layer indicates that the processing temperature was 388–419 ℃; thus, the formation mechanism was the transformation of solid solution in the amalgam to intermetallic compound during the heating of Au-Hg system. Moreover, the cross-sectional transition layer is mainly composed of Ag and Hg due to the interstitial diffusion of mercury atoms at room temperature and vacancy diffusion of silver atoms during the heating process, bonding the gold layer with the substrate. Obviously, the bonding mechanism of the gold layer and substrate was interstitial diffusion and vacancy diffusion within the Ag-Hg system. The current work reveals the special multilayered cross-section of silver gilding relics and shows that mercury played a crucial role in both the formation of the gold layer and bonding between the gold layer and substrate during the silver gilding process.

Soot Formation in Spherical Diffusion Flames

In the period from 2019 to 2022, the joint American–Russian space experiment (SE) Flame Design (Adamant) was carried out on the International Space Station (ISS). The purpose of the joint SE was to study the mechanisms of control of soot formation in a spherical diffusion flame (SDF) formed around a porous sphere (PS), and the radiative extinction of the SDF under microgravity conditions. The objects of this study were “normal” and “inverse” SDFs of gaseous ethylene in an oxygen atmosphere with nitrogen addition at room temperature and pressures ranging from 0.5 to 2 atm. A normal flame is a flame formed in an oxidizing atmosphere when fuel is supplied through the PS. An inverse flame is a flame formed in a fuel atmosphere when an oxidizer is introduced through the PS. This article presents the results of calculations of soot formation in normal and inverse SDFs. The calculations are based on a one-dimensional non-stationary model of diffusion combustion of gases with detailed kinetics of ethylene oxidation, supplemented by a macrokinetic mechanism of soot formation. The results indicate that soot formation in normal and inverse SDFs is concentrated in the region where the local C/O atomic ratio and local temperature satisfy the conditions 0.32 &lt; C/O &lt; 0.44 and T &gt; 1300–1500 K.

An environmentally friendly approach for the characterization of construction materials: determination of trace, minor, and major elements by slurry sampling high-resolution continuum source graphite furnace atomic absorption spectrometry.

A slurry sampling method was developed for the fast determination of Pb, Ni, Fe, and Mn in construction materials by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). For sample introduction into the GF, stable slurries were prepared by sonicating 10 mg of ground solid sample in 10.0 mL of 1% (v/v) Triton X-100 and 1% (v/v) HNO3 solution for 1.0 min. The determination of the four elements was carried out in three measurement runs, with Ni and Fe being determined simultaneously. The HR-CS GFAAS measurements were performed using analytical lines with adequate sensitivity, considering the content of each element in the material: Pb at 283.306 nm (42%), Mn at 403.080 nm (6.7%), Ni at 232.003 nm (100%) and Fe at 232.036 nm (1.4%). The pyrolysis and atomization temperatures and the use of chemical modifiers were optimized using both aqueous standards and slurry samples. At optimal conditions, samples with concentrations of Pb from 1.5 to 80 μg g-1, Ni from 4.0 to 75 μg g-1, Mn from 2.0 to 600 μg g-1, and Fe from 0.15 to 60 mg g-1 could be determined using a unique sample suspension. To assess the validity of the method, a fly ash certified reference material (CRM) was analysed using the slurry sampling HR-CS GFAAS method; this CRM and the construction material samples were also analysed by HR-CS GFAAS after the digestion of the samples. The obtained results using both methods were statistically comparable (Student's paired t-test for two independent methods at a 95% confidence level) demonstrating the suitability of the proposed method.

Application of Disposable Pipette Extraction for Determination of Yb by High‑Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry Using Lanthanum as a Chemical Modifier

The use of extraction technique with disposable tips (DPX) was applied for the first time for the extraction and preconcentration of Yb in samples of liquid waste from the petrochemical industry and environmental water using bioabsorbent cork. The use of cork as an extracting phase in the determination of Yb by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) was evaluated. The pyrolysis and atomization temperatures were optimized at 1400 and 2400 ºC, respectively. H2SO4, HNO3 and HCl acids were compared in the steps of cleaning the extraction phase and desorption of the analyte by DPX. The best extraction in the selected conditions was obtained with pH 8.0 and 5% v/v HCl. The recoveries were close to 100% for residual water and drinking water, 33 to 77% for produced water and 64 to 93% for river water. Tests with interfering ions in different concentrations were performed. The relative limit of quantification (LOQ) and limit of detection (LOD) were estimated at 0.03 and 0.01 µg L-1, respectively. The total time for the preparation of the samples by DPX was close to 1 min per sample. Extraction and pre-concentration were observed using DPX with a preenrichment factor of approximately 4 times.

Dispersive Liquid Phase Microextraction (DLPME) as a Strategy for CdII Separation and Determination in High-Salinity Produced Waters by Graphite Furnace Atomic Absorption Spectrometry

In this study, we propose a microextraction method for the determination of CdII in produced waters. The process is based on the conversion of CdII ions into a hydrophobic diethyldithiocarbamate (DDTC) complex with its subsequent dispersive liquid phase microextraction (DLPME) from the aqueous medium with chloroform. The organic phase was then diluted with ethanol and Cd absorbance was measured by graphite furnace atomic absorption spectrometry (GF AAS). The experimental conditions related to the DLPME process were investigated, and the best microextraction conditions were achieved at pH = 6.0 (acetate buffer), 7.5 × 10-6 mol L-1 of DDTC, and when using 200 µL of chloroform as the extracting solvent. No dispersing solvent was needed, which allowed the recovery of approximately 140 µL of chloroform extract. Pyrolysis and atomization temperatures of the GF AAS program were determined through the construction of the respective curves. The estimated limits of detection (LOD) and quantification (LOQ) were 5 and 17 ng L-1, respectively, whereas the enrichment factor for the method was 17. Six samples of seawater and five samples of produced waters with salinities between 30 and 270‰ were analyzed as well as two certified reference materials of saline waters.

Precision Magnetic Field Sensing with Dual Multi-Wave Atom Interferometer.

Precision magnetic field measurement is widely used for practical applications, fundamental research, and medical purposes, etc. We propose a novel quantum magnetometer based on atoms' multi-wave (3-wave and 5-wave) Ramsey interference. Our design features high phase sensitivity and can be applied to in situ measurements of the magnetic field inside vacuum chambers. The final state detection is designed to be achieved by Raman's two-photon transition. The analytical solution for applicable interference fringe is presented. Fringe contrast decay due to atom temperature and magnetic field gradient is simulated to estimate reasonable experimental conditions. Sensitivity functions for phase noise and magnetic field noise in a multi-wave system are derived to estimate the noise level required to reach the expected resolution. The validity of the model, dual-channel features on bias estimation, and the quasi-non-destructive detection feature are discussed.