Building and Programming a Universal Ion Trap Quantum Computer
| dc.contributor.advisor | Monroe, Christopher | en_US |
| dc.contributor.author | Figgatt, Caroline | en_US |
| dc.contributor.department | Physics | en_US |
| dc.contributor.publisher | Digital Repository at the University of Maryland | en_US |
| dc.contributor.publisher | University of Maryland (College Park, Md.) | en_US |
| dc.date.accessioned | 2018-07-17T06:20:57Z | |
| dc.date.available | 2018-07-17T06:20:57Z | |
| dc.date.issued | 2018 | en_US |
| dc.description.abstract | Quantum computing represents an exciting frontier in the realm of information processing; it is a promising technology that may provide future advances in a wide range of fields, from quantum chemistry to optimization problems. This thesis discusses experimental results for several quantum algorithms performed on a programmable quantum computer consisting of a linear chain of five or seven trapped 171Yb+ atomic clock ions with long coherence times and high gate fidelities. We execute modular one- and two-qubit computation gates through Raman transitions driven by a beat note between counter-propagating beams from a pulsed laser. The system's individual addressing capability provides arbitrary single-qubit rotations as well as all possible two-qubit entangling gates, which are implemented using a pulse-segmentation scheme. The quantum computer can be programmed from a high-level interface to execute arbitrary quantum circuits, and comes with a toolbox of many important composite gates and quantum subroutines. We present experimental results for a complete three-qubit Grover quantum search algorithm, a hallmark application of a quantum computer with a well-known speedup over classical searches of an unsorted database, and report better-than-classical performance. The algorithm is performed for all 8 possible single-result oracles and all 28 possible two-result oracles. All quantum solutions are shown to outperform their classical counterparts. Performing parallel operations will be a powerful capability as deeper circuits on larger, more complex quantum computers present new challenges. Here, we perform a pair of 2-qubit gates simultaneously in a single chain of trapped ions. We employ a pre-calculated pulse shaping scheme that modulates the phase and amplitude of the Raman transitions to drive programmable high-fidelity 2-qubit entangling gates in parallel by coupling to the collective modes of motion of the ion chain. Ensuring the operation yields only spin-spin interactions between the desired pairs, with neither residual spin-motion entanglement nor crosstalk spin-spin entanglement, is a nonlinear constraint problem, and pulse solutions are found using optimization techniques. As an application, we demonstrate the quantum full adder using a depth-4 circuit requiring the use of parallel 2-qubit operations. | en_US |
| dc.identifier | https://doi.org/10.13016/M2K35MH5F | |
| dc.identifier.uri | http://hdl.handle.net/1903/21008 | |
| dc.language.iso | en | en_US |
| dc.subject.pqcontrolled | Quantum physics | en_US |
| dc.subject.pqcontrolled | Atomic physics | en_US |
| dc.subject.pqcontrolled | Computer science | en_US |
| dc.subject.pquncontrolled | Atomic physics | en_US |
| dc.subject.pquncontrolled | Quantum computing | en_US |
| dc.subject.pquncontrolled | Quantum information | en_US |
| dc.subject.pquncontrolled | Quantum physics | en_US |
| dc.subject.pquncontrolled | Qubits | en_US |
| dc.subject.pquncontrolled | Trapped ions | en_US |
| dc.title | Building and Programming a Universal Ion Trap Quantum Computer | en_US |
| dc.type | Dissertation | en_US |