A5075998039- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced MRI Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Advanced Frequency and Time Standards
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Advanced Fiber Laser Technologies
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Solid-state spectroscopy and crystallography
- Scientific Research and Discoveries
- NMR spectroscopy and applications
- Bone Tissue Engineering Materials
- Blind Source Separation Techniques
- Functional Brain Connectivity Studies
- Particle physics theoretical and experimental studies
- Diamond and Carbon-based Materials Research
- EEG and Brain-Computer Interfaces
- Semiconductor materials and devices
- Semiconductor Lasers and Optical Devices
Peking University
2013-2024
Nanjing Institute of Agricultural Mechanization
2022-2024
Ministry of Agriculture and Rural Affairs
2024
Xidian University
2024
Xi'an University of Science and Technology
2024
Helmholtz Institute Mainz
2017-2021
Johannes Gutenberg University Mainz
2017-2021
GSI Helmholtz Centre for Heavy Ion Research
2020-2021
IBM (United States)
1984-2021
OmniVision Technologies (Germany)
2021
High-sensitivity total-field atomic magnetometer enables brain-activity measurements in unshielded Earth’s field.
Magnetocardiography (MCG), which uses high-sensitivity magnetometers to record magnetic field signals generated by electrical activity in the heart, is a noninvasive method for evaluating heart diseases such as arrhythmia and ischemia. The MCG measurements usually require participant keeping still magnetically shielded room due immovable sensor noisy external environments. These requirements limit applications, exercise tests long-term observations, are useful early detections of diseases....
We report the results of a search for axionlike dark matter using nuclear magnetic resonance (NMR) techniques. This is part multi-faceted Cosmic Axion Spin Precession Experiment (CASPEr) program. In order to distinguish from fields, we employ comagnetometry scheme measuring ultralow-field NMR signals involving two different nuclei ($^{13}$C and $^{1}$H) in liquid-state sample acetonitrile-2-$^{13}$C ($^{13}$CH$_{3}$CN). No signal was detected above background. result constrains parameter...
The nature of dark matter, the invisible substance making up over 80% matter in universe, is one most fundamental mysteries modern physics. Ultralight bosons such as axions, axion-like particles, or photons could make matter. Couplings between and nuclear spins may enable their direct detection via magnetic resonance (NMR) spectroscopy: As move through galactic dark-matter halo, they couple to behave if were an oscillating field, generating a dark-matter-driven NMR signal. part cosmic axion...
We report the results of an experimental search for ultralight axion-like dark matter in mass range 162 neV to 166 neV. The detection scheme our Cosmic Axion Spin Precession Experiment (CASPEr) is based on a precision measurement $^{207}$Pb solid-state nuclear magnetic resonance polarized ferroelectric crystal. Axion-like can exert oscillating torque spins via electric-dipole moment coupling $g_d$, or gradient $g_{\text{aNN}}$. calibrated detector and characterized excitation spectrum...
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...
We present a highly sensitive miniaturized cavity-enhanced room-temperature magnetic-field sensor based on nitrogen-vacancy (NV) centers in diamond. The magnetic resonance signal is detected by probing absorption the 1042\,nm spin-singlet transition. To improve absorptive diamond placed an optical resonator. device has sensitivity of 28 pT/$\sqrt{\rm{Hz}}$, projected photon shot-noise-limited 22 pT/$\sqrt{\rm{Hz}}$ and estimated quantum projection-noise-limited 0.43 with sensing volume...
Polarization spectroscopy in (4)He around 1083 nm is observed and optimized with a distributed feedback fiber laser applied for frequency stabilization. In order to improve the accuracy long-term stability of frequency-locking performance, power stabilization module added, dependences peak-to-peak amplitude difference (width) polarization signal on various pump probe powers are investigated.
We show that in a spin system of two magnetically inequivalent protons coupled to heteronucleus such as 13C, an adiabatic magnetic field sweep, passing through zero field, transfers the proton singlet order into magnetization heteronucleus. This effect is potentially useful parahydrogen-enhanced nuclear resonance and demonstrated on singlet-hyperpolarized [1-13C]maleic acid, which prepared via reaction between [1-13C]acetylene dicarboxylic acid para-enriched hydrogen gas. The sweeps are...
Searching for beyond-the-standard-model interactions has been of interest in quantum sensing. Here, we demonstrate a method, both theoretically and experimentally, to search the spin- velocity-dependent interaction with an atomic magnetometer at centimeter scale. By probing diffused optically polarized atoms, undesirable effects coming along optical pumping, such as light shifts power-broadening effects, are suppressed, which enables 1.4 fT_{rms}/Hz^{1/2} noise floor reduced systematic...
The cosmic axion spin precession experiment (CASPEr) is a nuclear magnetic resonance (NMR) seeking to detect and axion-like particles which could make up the dark matter present in Universe. We review predicted couplings of axions with baryonic that enable their detection via NMR. then describe two measurement schemes being implemented CASPEr. first method, presented original CASPEr proposal, consists resonant search continuous-wave NMR spectroscopy. This method offers highest sensitivity...
Zero- to ultralow-field (ZULF) nuclear magnetic resonance (NMR) is an emerging tool for precision chemical analysis. In this work, we study dynamic processes and investigate the influence of exchange on ZULF NMR J-spectra. We develop a computational approach that allows quantitative calculation J-spectra in presence apply it aqueous solutions [15N]ammonium (15N[Formula: see text]) as model system. show pH-dependent substantially affects and, some cases, can lead degradation complete...
Abstract A series of reactive, end-capped, polyimide oligomers has been prepared for possible use as planarizing coatings in the electronics industry. Thus, 1,3-bis(3-aminophenoxy)benzene was treated with various excess amounts 2,2-bis(3,4-dicarboxyphenyl)hexafluoro-propane dianhydride m-cresol containing toluene and isoquinoline. The resulting anhydride-terminated amic-acid were thermally imidized then allowed to react 3-aminophenylethyne, 1-phenyl-4-(3-aminophenyl)buta-1-ene-3-yne,...
We propose a new type of optical resonator that consists embedded ring resonators (ERRs). The exhibit unique amplitude and phase characteristics allow designing compact filters, modulators, delay elements. A basic configuration the ERRs with two rings coupled in point-to-point manner is discussed under operating conditions. An ERR-based microring modulator shows high operation speed up to 30 GHz. distributed coupling are briefly described as well.
Atomic comagnetometers are used in searches for anomalous spin-dependent interactions. Magnetic field gradients one of the major sources systematic errors such experiments. Here we describe a comagnetometer based on nuclear spins within an ensemble identical molecules. The dependence measured spin-precession frequency ratio first-order magnetic gradient is suppressed by over order magnitude compared to overlapping ensembles different Our single-species capable measuring hypothetical...
As a complement to conventional high-field nuclear magnetic resonance (NMR), zero- and ultralow-field (ZULF) NMR has important applications in chemical analysis fundamental physics. Breakthroughs this field are being thwarted part by intrinsic susceptibility noise. This study uses two-channel atomic magnetometer eliminate common-mode approach could promote the engineering of portable ZULF-NMR system, provide sensitive method probe frontiers physics, such as exotic spin-dependent interactions...
Aiming at weak representation ability and severe loss of time series features in the traditional methods when facing large-scale complex power load forecasting tasks, an LSTM-Autoencoder model that integrates long-term short-term samples is proposed for forecasting. The encoder part simultaneously receives long short as input to extract different levels generate related latent vectors. decoder tries reconstruct sequence while outputting prediction results ensure vectors are meaningful. In...
An overview of our experimental program to search for axion and axion-like-particle (ALP) dark matter using nuclear magnetic resonance (NMR) techniques is presented. oscillating field can exert a time-varying torque on spins either directly or via generation an electric dipole moment (EDM). Magnetic be used detect such effect. The first-stage experiments explore many decades ALP parameter space beyond the current astrophysical laboratory bounds. It anticipated that future versions will...
Zero-field nuclear magnetic resonance (NMR) provides complementary analysis modalities to those of high-field NMR and allows for ultra-high-resolution spectroscopy measurement untruncated spin-spin interactions. Unlike the case, however, universal quantum control -- ability perform arbitrary unitary operations has not been experimentally demonstrated in zero-field NMR. This is because Larmor frequency all spins identically zero at field, making it challenging individually address different...
Abstract We demonstrate a single-beam three-axis parametric-resonance magnetometer operated in near-zero fields. By reflecting the incident laser beam at 90° vapor cell and applying three orthogonal parametric modulation fields, components of magnetic field can be extracted from transmitted light signal. Our vector experimentally demonstrates magnetic-field sensitivities 30 fT Hz −1/2 along x - y -axes 70 z -axis, features compact architecture, which is particularly attractive for...
Magnetic-field-gradient-induced spin polarization transverse relaxation is re-examined in an alkali-metal atomic cell with antirelaxation coating. The experimentally observed motional-narrowing effect a paraffin-coated vapor cell, phenomenon for depicting the suppression of caused by magnetic-field gradient, more than order magnitude weaker theoretical predictions. Such discrepancy due to existence background gas. By taking gas into consideration, Redfield theory combined Langevin approach...
We propose and demonstrate a radio-frequency (rf) atomic magnetometer based on parametric resonances. Previously, most rf magnetometers are magnetic resonances their sensitivities often limited by spin-exchange relaxation. Here, we introduce novel scheme for an where the field is measured exciting instead of using modulation fields. In this way, relaxation almost eliminated. Benefiting from low spin rate, resonance exhibits narrower linewidth stronger signal, which results in higher...
A magnetically-quiet environment is important for detecting faint magnetic-field signals or nonmagnetic spin-dependent interactions. Passive magnetic shielding using layers of large magnetic-permeability materials widely used to reduce the noise. The noise can also be actively monitored with magnetometers and then compensated, acting as a complementary method passive shielding. We present here general model quantitatively depict optimize performance active stabilization experimentally verify...