Speaker
Description
Molecules have rich energy level structures with transitions ranging from the kHz to PHz range, some of which exhibiting excellent coherence properties. Molecules are therefore promising for quantum information processing, as well as precision measurements, e.g. realizing quantum sensors and novel clocks, in particular for testing fundamental physics.
However, the lack of cycling transitions is a challenge for both laser cooling and state detection and thus for high-precision spectroscopic measurements.
In this context, molecular ions co-trapped with atomic ions are very promising. The atomic ions contain cycling transitions and laser cooling is achieved by a combination of Dopplerand sideband cooling. Due to the Coulomb interaction between the atomic and molecular ions, the latter can be indirectly or ‘sympathetically’ cooled to the motional ground state. The interaction can also be used for state detection of the molecular ions through quantum logic spectroscopy schemes.
The goal of this project is to achieve motional ground-state cooling of a two-ion system of SrH+ and Sr+. This will allow the implementation of quantum logic protocols to coherently manipulate the molecular (ro)vibrational energy levels. To span the wide range of energy levels, several laser technologies will be used. Purely rotational transitions in the THz range,are covered by driving stimulated Raman transitions with a frequency comb. Vibrational transitions in the near-infrared, will be reached with a stabilized quantum cascade laser. In particular, this project will pave the way towards realizing a molecular clock and to search for time variations of the electron to proton mass ratio.
As of now, we have trapped Sr+ ions and performed mass measurements of co-trapped molecular ions. We are preparing the first spectroscopic measurements of SrH+ and SrOH+.
| Academic level | PhD student |
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