The world is mostly neutral. That is, most of the atoms in our environment are electrically neutral. The number of electrons in the outer parts of atoms equals the number of protons at the centers of atoms. As one or more electrons are plucked away from the atoms, the remaining electrons feel a much stronger positive pull from the nucleus. This enhanced pull, causing the atoms to shrink in size, ensures that those electrons are less vulnerable to the distractions of their environment, making them potentially valuable for next-generation atomic clocks, for quantum information schemes (where the loss of quantum coherence in qubits is a paramount danger), and for experiments trying to detect slight variations in the fine structure constant, the parameter that sets the overall strength of the electromagnetic force.
A new theoretical study conducted by JQI adjunct fellow Marianna Safronova and her colleagues from groups around the world (1) provides the best yet study of how highly charged ions could be used for atomic timekeeping and for processing quantum information. They identify 10 such ions---for instance, samarium-14+ and neodymium-10+---along with estimates of ion properties experimenters need to know before beginning their work, things such as the expected lifetimes and internal energy levels for the excited states of the ions.
WORKING WITH HIGHLY CHARGED IONS
Charged-up atoms are hard to produce and control. At one of the facilities dedicated to this purpose, the Electron Beam Ion Trap (EBIT) at the Lawrence Livermore National Lab, a beam of electrons intercepts a beam of atoms, ionizing the atoms at they go. In this way charge states all the way up to +92 (fully ionized uranium atoms) have been achieved. The trick is to store such charged ions and to cool them to low temperatures. In the kind of atomic environments typical of atomic clocks or quantum computers, low temperature means small io
|Contact: Phillip F. Schewe|
Joint Quantum Institute