NIST physicists have successfully “flash-frozen” a flat crystal of 150 beryllium ions, a significant advancement in quantum technology. By cooling the ions to one-third of the energy carried by a single phonon (a packet of motional energy), the researchers achieved groundstate cooling for all 150 drumhead vibrations in the crystal. This level of cooling is close to the quantum-mechanical ground state for the crystal’s vibrations, making it a more realistic simulator of quantum magnetism and enabling more complex entangled quantum systems for quantum sensing applications.
The achievement builds on previous work by another group cooling a line of 18 ions. The NIST team used two lasers to cool the crystal, inducing the ions to lose energy without adding to their motion. The method cooled the drumhead vibrations, which have the most practical uses in quantum simulations and sensing. With groundstate cooling, the ion crystal can potentially sense very weak electric fields, enabling searches for certain types of dark matter like axions and hidden photons.
The research was supported by the National Science Foundation, Defense Advanced Research Projects Agency, Air Force Office of Scientific Research, and Army Research Office. Future work will focus on cooling three-dimensional crystals with larger numbers of ions.
Source: https://www.nist.gov/news-events/news/2019/02/nist-physicists-flash-freeze-crystal-150-ions
Keywords: ion, crystal, quantum, magnetism, sensing
