Cryogenic ion trap system for high-fidelity near-field microwave-driven quantum logic (2f. Advanced Computing)
Abstract
Within the last year, we have demonstrated that near-field microwave control of trapped-ion qubits is possible with fidelities approaching the state-of-the-art previously attained only with laser-driven techniques. We achieved a two-qubit gate fidelity of 99.7% [Harty 2016] and, in a separate experiment, individual qubit addressing with precision above 99.5% [Aude Craik 2017]. These demonstrations show that purely electronic control of trapped-ion qubit logic operations is a viable alternative to laser methods, and removes the need for the most technically demanding laser systems in a trapped-ion quantum information processor. The maturity of microwave electronics, and the relative ease of integrating microwave circuitry with the ion trap electrode structure, make these techniques a compelling alternative to laser methods. Although the fidelities hitherto achieved are already above the minimum threshold levels (~99%) for fault-tolerant quantum computation, for realistic overheads it is necessary to improve the fidelities substantially. The two-qubit gate duration (3ms) was also more than an order of magnitude slower than that of the highest-fidelity laser gates. In this proposal, we target an improvement in both the gate fidelity and speed of approximately an order of magnitude. We will achieve this by using a novel trap geometry and qubit, both optimised for near-field microwave work, as well as by reducing the size of the trapping structures. Additionally, we will cool the apparatus to cryogenic (T ~ 20K) temperatures to suppress electric field noise, and develop a more sophisticated microwave drive system. The design of this second-generation apparatus will take advantage of our experience with the first-generation Oxford microwave ion trap.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810340
Entities
People
- David Lucas
Organizations
- Army Contracting Command
- National Security Agency
- University of Oxford