Design and operation of a Penning ion trap for quantum simulation

Abstract

In the search for new computational paradigms past the impending end of Moore’s law quantum information processing based on cold trapped ions has emerged as a promising candidate. This thesis presents on the design, construction and testing of a setup for analog quantum simulation experiments using Be ion crystals in a Penning trap. At the heart of the experiment is a specialized Penning trap with wide optical access for engineering Ising-type interactions. The trap sits inside a superconducting magnet which runs continuously with minimal losses through a novel dual-stage reliquefier system. During this thesis, mechanical and optical subsystems for this ion trap quantum simulator were designed and built. Two laser systems based on nonlinear frequency conversion were set up to generate light for photoionization, Doppler cooling, state preparation, readout, and Raman interactions. In parallel, a method was devised to produce ultraviolet-solarization resistant fiber patch cords for pointing-stable light delivery. Inbore optomechanics and a collaboratively designed precision six-axis positioning device were constructed for beam delivery and trap alignment, respectively. These optomechanics co-locate custom-designed millimeterwave delivery systems as well as numerically optimized, diffraction-limited imaging optics for fluorescence readout. Using these subsystems, we validate interferometrically the motional stability of the setup from the mHz to kHz region during pulse-tube operation. First-ever light-ion interaction serves to validate calculations of interaction frequencies, optomechanics operation, and imaging performance, while coherent qubit interaction allows for this to be done on the millimeter wave setup, where initial Rabi flopping times of 18 us were observed. Site-resolved imaging of rapidly rotating ion crystals demonstrates critical phase-locked operation of the apparatus; positioning the experiment for future upgrades towards a full analog quantum simulator.