Erwin Schrödinger Center for Quantum Science & Technology (ESQ)

SDEF: State-dependent Force Spectroscopy for Trapped Ions

Optical trapping and laser cooling are the foundation of revolutionary quantum experiments in which atoms and molecules are manipulated using optical forces induced by light. A particularly useful technique are optical tweezers which are routinely used in many scientific disciplines. On the other hand, trapped ions are an excellent basis for useful quantum devices due to the available state preparation and read-out at the single atom level. Within this project, we aim to combine state-dependent optical tweezers to manipulate the motional modes of an ion crystal with the idea of quantum logic spectroscopy. We plan to co-trap a well controllable Calcium logic ion together with a molecular ion of interest which is inaccessible to the standard spectroscopic techniques. We will apply a state-dependent force on the molecule with an optical tweezer which modifies the overall trapping potential. This change in potential consequently shifts the frequency of the ions common motional mode which can be measured via the logic ion. Thereby we realize a quantum non-demolition measurement of the molecules internal state. We think that this project will facilitate the non-destructive state detection of molecules with the outlook of providing a basis for a compact spectrometer for atomic and molecular systems.