原子物理
Circularly polarized light offers opportunities to probe symmetry-dependent properties of matter such as chirality and spin. Circular dichroism measurements typically require further intrinsic or extrinsic breaking of symmetry by e.g.…
We report a systematic uncertainty of $9.2\times 10^{-19}$ for the USTC Sr1 optical lattice clock, achieving accuracy at the level required for the roadmap of the redefinition of the SI second. A finite-element model with {\it in…
Nuclear spin comagnetometers offer exceptional precision in measurements of spin energy levels and exhibit long-term stability, making them powerful tools for probing spin-dependent physics beyond the Standard Model as well as for inertial…
The rates of elastic and inelastic scattering processes of spin-polarized atomic tritium are vital inputs for the design and operation of experiments using cold, magnetically trapped tritium atoms. Elastic scattering dominates the total…
We present a method for determining the azimuthal phase (angle) of a magnetic field by exploiting phase matching of laser beams in a ground-state Hanle effect (GHSE) configuration. This approach is based on the symmetry of the system's…
The optical cycle-averaged ionization rate of Ar, O$_{2}$, and N$_{2}$ vs. local instantaneous laser intensity $I$ for linear polarized $800$ nm light is determined up to approx. $300$ TW/cm$^{2}$ by numerically inverting published…
We have investigated strong-field-induced electronic coherences in argon and molecular nitrogen ions created by high-intensity, few-cycle infrared laser pulses. This is a step toward the long-sought goal of strong-field coherent control in…
We investigate the dynamical phase evolution of Coulomb-focused electrons in strong-field ionization. We diffract the electrons with an ultrashort standing light wave to track their time-dependent phase. Our findings show that low-energy…
We present a MATLAB script which can use GPU acceleration to simulate a trapped ion interacting with a low-density cloud of atoms. This script, called atomiongpu.m, can massively parallelize MD simulations of trajectories of a trapped ion…
We present a geometric interpretation of the hyperfine Breit--Rabi eigenvalues and eigenvectors in alkali atoms after reformulating the standard solution into a compact form. In this picture, the nuclear magnetic moment has a polar angle…
Searches for the nuclear magnetic quadrupole moment (MQM) and nuclear Schiff moment (NSM) have high discovery potential for violations of time ($T$) and parity ($P$) reversal symmetries beyond the Standard Model. Molecules containing heavy…
We present the first implementation of modulation transfer spectroscopy (MTS) on the D$1$ line of $^7$Li, carried out in a compact heat-pipe vapor cell with cold windows. By varying the pump and probe intensities and polarization…
The FAMU experiment, supported and funded by the Italian Institute of Nuclear Physics (INFN) and by the Science and Technology Facilities Council (STFC), aims to perform the first measurement of the ground-state hyperfine splitting (1S-hfs)…
The right kind of theoretical treatment of direct Coulomb ionization of inner-shell of target atoms including multiple ionization of their outer-shells by using accurate x-ray fluorescence yield data and electron capture by projectile ions…
The previously applied independent atom model (IAM) for highly charged ion-molecule collisions which implemented the suppression of multiple ionization and capture on the basis of geometric overlaps of cross-sectional areas representing…
Efficient quantum-state detection is crucial for many precision control experiments, such as the ongoing effort to probe the electron's electric dipole moment using trapped molecular $^{232}\mathrm{ThF}^+$ ions at JILA. While quantum state…
In the tunneling regime and at sufficiently low field amplitudes, the shape of orientation-dependent molecular ionization rate curves usually resembles the shape of the ionized orbital. As the ionizing field strength increases, the shape of…
Searches for physics beyond the Standard Model using spin sensors are susceptible to spurious frequency shifts and noise due to magnetic fields. Therefore a comagnetometer -- an auxiliary sensor that allows mundane magnetic field effects to…
Dark-state polaritons (DSPs) based on the effect of electromagnetically induced transparency are bosonic quasiparticles, representing the superpositions of photons and atomic ground-state coherences. It has been proposed that stationary…
We report a joint experimental and theoretical study using a combination of polarization-controlled free-electron-laser (FEL) and near-infra\-red (NIR) pulses in a synchronized two-color photo\-ionization scheme. Excited He$^+$ ions,…