Magneto-optical trapping of Zinc

Abstract

We report on laser cooling and magneto-optical trapping of atomic zinc. The atoms are cooled using the 213.9\,nm $^1$S$_0$ $\rightarrow$ $^1$P$_1$ transition, making this the shortest wavelength employed for magneto-optical trapping thus far. We demonstrate trapping of all stable isotopes of zinc, including the fermionic isotope $^{67}$Zn, which features a very narrow $^1$S$_0$ $\rightarrow$ $^3$P$_0$ transition that could form the basis of an optical atomic clock. We characterize the influence of various parameters on the MOT population and loading rate. The results presented here constitute the first step towards the application of zinc for high-precision optical spectroscopy and quantum information processing.

Figures (5)

• Figure 1: Partial level diagram of zinc, showing transitions relevant for laser cooling and precision spectroscopy, as well as their wavelengths $\lambda$ and natural linewidths $\Gamma/2\pi$. For the two states relevant to this work, the hyperfine splitting of the fermionic isotope $^{67}$Zn is shown as wll.
• Figure 2: (a) Schematic representation of the experimental chamber. (b) Schematic representation of the 214-nm laser system.
• Figure 3: A fluorescence image of a MOT of zinc atoms, as captured by the CCD camera. This image was taken with $P_0 = 62$ mW, $\delta B = 125$ G/cm, and $\Delta = 75$ MHz.
• Figure 4: (a) MOT population in dependence of the detuning, given relative to the transition frequency of $^{64}$Zn. (b) Positions of the resonance frequencies for each isotopes, with heights corresponding to the abundance of that isotope.
• Figure 5: (a) MOT population in dependence of the magnetic gradient field strength, for $T = 230$ °C, $P_0 = 50$ mW, and $\Delta = 100$ MHz. (b) Dependence of the MOT population on the optical power of the cooling laser, for $T = 230$ °C and $\delta B = 125$ G/cm. (c) Dependence of MOT population on the oven temperature, for $P_0 = 50$ mW, $\Delta = 2\pi \cdot 100$ MHz, and $\delta B = 125$ G/cm. (d) Loading time in dependence of the optical power and for different temperatures, at $\Delta = 100$ MHz and $\delta B = 125$ G/cm