Operation of micron-scale 3D-printed ion traps at cryogenic temperatures

Small, machine-fabricated ion traps are a promising route to address the challenge of scalability for trapped ion quantum information science. We have developed a cryogenic ion trapping apparatus aimed at efficient prototyping for 3D-printed traps designs fabricated using a two-photon polymerization process. These traps are comparable in size to their surface trap analogues, but their three-dimensional electrode structure generates a deeper trapping potential. Additionally, the two-photon polymerization fabrication supports complex trap structure designs and is compatible with integrated photonics, making these traps amenable to ion motional operations necessary for the quantum charge-coupled device (QCCD) architecture and portable optical clocks. We have benchmarked our cryogenic system by measuring motional heating rates in a surface trap from MIT Lincoln Labs, and are now working with the first generation of horizontal 3D-printed traps. In the 3D traps, we have trapped Sr+ crystals, measured trap secular frequencies, and performed spectroscopy on the trapped ions. We are currently studying the dependence of motional heating rates on trap frequency in a 3D-printed horizontal trap.