Compatibility of trapped ions and dielectrics at cryogenic temperatures

We study the impact of an unshielded dielectric x2013 here, a bare optical fiber x2013 on a ⁴⁰Ca⁺ ion held several hundred $μ$m away in a cryogenic surface electrode trap. We observe distance-dependent stray electric fields of up to a few kV/m due to the dielectric, which drift on average less than 10% per month and can be fully compensated with reasonable voltages on the trap electrodes. We observe ion motional heating rates attributable to the dielectric of ≈30 quanta per second at an ion-fiber distance of 215(4) $μ$m and ≈1.5 MHz motional frequency. These results demonstrate the viability of using unshielded, trap-integrated dielectric objects such as miniature optical cavities or other optical elements in cryogenic surface electrode ion traps.