arXiv subjects

Zhuxiong Ye

Publications and source records attributed to Zhuxiong Ye.

4 recordsLinked to original sources

arXiv2026

Magnetic-Field-Calibration-Free Determination of the Hyperfine Constant $A$ in Ultracold Fermi gases of $^{40}$K

Hyperfine constant $A$ is a key parameter of the hyperfine structure and underpins precision spectroscopy and metrology. In this Letter, we develop a magnetic-field-calibration-free method for determining the ground-state hyperfine constant $A$ in an ultracold $^{40}$K Fermi gas by utilizing a pair of magnetically insensitive ("clock") transitions. This overcomes the stringent magnetic-field calibration requirements of conventional methods. We measure the transition frequency between these two magnetically insensitive transitions with Hz-level resolution over a range of magnetic fields, and obtain the ground-state hyperfine constant $A = -h\times 285.730536(2)\,\mathrm{MHz}$, corresponding to an absolute uncertainty of about $2\,\mathrm{Hz}$. Our value reduces the uncertainty by nearly three orders of magnitude compared with previous determinations, providing a substantially improved reference for high-precision spectroscopy and metrology with $^{40}$K.

cond-mat.quant-gas↗

arXiv2026

Experimental study of matter-wave four-wave mixing in $^{39}$K Bose-Einstein condensates with tunable interaction

We experimentally investigate four-wave mixing (FWM) of matter waves in two geometric configurations in $^{39}$K Bose-Einstein condensates with the atomic interaction tuned via Feshbach resonances. For one configuration with the single-spin component, the FWM yield increases with a larger scattering length. For the two-spin component configuration, we specifically investigate FWM in both the droplet and gas parameter regimes. We find that the FWM yield reaches its maximum near the critical parameter region between the gas and droplet phases. Our research can help to optimize the FWM yield for matter-wave amplification and entangled atom pair generation, making it conducive to applications in quantum information processing and precision measurement.

cond-mat.quant-gas↗

arXiv2026

Experimental study of magnetically insensitive transitions in ultracold Fermi gas of $^{40}$K

This paper presents an experimental study of microwave single-photon transitions that are magnetic-field-insensitive in degenerate Fermi gases of $^{40}$K. This contrasts with microwave single-photon clock transitions for 0-0 magnetic-field-insensitive states and two-photon clock transitions for non 0-0 magnetic-field-insensitive states in bosonic alkali metal atoms. We show that there are two sets of special transitions between two different hyperfine ground states ($|F$=9/2, $m_{F}$=1/2$\rangle$ $\Leftrightarrow$ $|$7/2, -1/2$\rangle$ and $|$9/2, -1/2$\rangle$ $\Leftrightarrow$ $|$7/2, 1/2$\rangle$), whose microwave single-photon transition frequency is insensitive to low magnetic fields, as the first-order Zeeman shift is almost completely canceled. By using the microwave spectrum and Ramsey interference fringes, we demonstrate the long-time stability of the coherent transition under magnetic field fluctuations. These magnetic-field-insensitive microwave hyperfine transitions in ultracold $^{40}$K Fermi gases offer promising applications in quantum information and precision measurements.

cond-mat.quant-gas↗

arXiv2019

A dual-species magneto-optical trap for lithium and strontium atoms

We present a machine built for experiments with ultracold mixtures of strontium and lithium atoms. The machine includes a science vacuum chamber and the relevant laser systems for cooling and trapping the atoms. With this machine, we realize a D2-line compressed magneto-optical trap (MOT) for ${^6}$Li and a narrow-linewidth 689-nm MOT for $^{84}$Sr, obtaining ~$10^9$ ${^6}$Li atoms at 700 $μ$K and ~$10^7$ $^{84}$Sr atoms at 1.8 $μ$K. Such a dual-species MOT provides an ideal starting point for realizing double degenerate mixtures of $^6$Li and Sr atoms.

cond-mat.quant-gas↗