Engineering and Operating a Trapped-Ion Quantum Computer

We present the system design and architecture of a trapped-ion universal quantum processor with high-fidelity quantum gates and addressing of up to 32 qubits. Our approach takes advantage of individual optical addressing to achieve simultaneous high-fidelity operations on a long chain of 171Yb+ ions, resulting in one of the largest academic general-purpose quantum computers. One of the factors limiting performance of a large trapped ion quantum processor is excess electric-field noise that causes ion heating. We will present results from electric-field noise studies performed at high temperatures, which can be described by a model related to defect motion in metal films. As a first test of the system functionality, we implement aspects of quantum error correction, including the encoding of the logical qubit, stabilizer readout, and logical gates. We also describe an ongoing effort to experimentally realize a purification phase transition in a monitored non-equilibrium many-body quantum system.