Molecules with multiple optically-active metal centers have unique applications in quantum science and precision measurements.
Some metals can make chemical bonds that leave many of the “atom-like” features intact, for example the ability to scatter multiple photons without exciting internal molecular modes - also known as optical cycling. This remains true even for many polyatomic molecules, as long as the bond that the metal sees is strong and involves the correct number of electrons. Most applications only need one metal center, but why not have several? If the optical cycling properties of a metal only depend on the bond to that metal, then large molecules should be able to support multiple, quasi-independent optical cycling centers. This could have many interesting applications for quantum information processing, quantum sensing, and precision measurements.
Figure: Ground and excited state orbitals for the molecules YbCCCa, calculated by Matt O'Rourke. The ground state corresponds to an electron localized on each of the Ca (a) and Yb (b) metals. There are also excited, metal-centered electronic states (c, d, and e) that can be used to cycle photons.
For example, one atom could be the primary qubit/sensor, and the other could be used for laser-cooling, environmental monitoring, or state preparation/readout/heralding/etc. via couplings between the two atoms. This also relaxes requirements on the photon cycling properties of the qubit/sensor atom, which enables advanced quantum control methods for atoms that don’t make bonds amenable to photon cycling.
We are part of the Molecules Functionalized with Optical Cycling Centers (MFOCC) Collaboration, funded by the DOE Office of Science through the Quantum Information Science program. Our goal is to explore applications of exotic molecules, both theoretically and experimentally, to realize applications in quantum science.
Molecules Functionalized with Optical Cycling Centers (MFOCC) Collaboration
Anastassia Alexandrova, UCLA Chemistry and Biochemistry
Wesley Campbell (Collaboration head and fearless leader), UCLA Physics and Astronomy
Justin Caram, UCLA Chemistry and Biochemistry
John M. Doyle, Harvard Physics
Eric Hudson, UCLA Physics and Astronomy
Nick Hutzler, Caltech Physics
Anna Krylov, USC Chemistry
Garnet Chan and Matt O'Rourke, Caltech Chemistry