Scaling Ion-trap Quantum Computing

Colin Bruzewicz, John Chiaverini, Robert McConnell +1 more

Trapped ions are among the most promising systems for practical quantum computing (QC). The basic requirements for universal QC have all been demonstrated with ions, and quantum algorithms using few-ion-qubit systems have been implemented. We review the state of the field, covering the basics of how trapped ions are used for QC and their strengths and limitations as qubits. In addition, we discuss what is being done, and what may be required, to increase the scale of trapped ion quantum computers while mitigating decoherence and control errors. Finally, we explore the outlook for trapped-ion QC. In particular, we discuss near-term applications, considerations impacting the design of future systems of trapped ions, and experiments and demonstrations that may further inform these considerations.

R. Blatt, Wolfgang Lange

Mark S. Gulley, Richard Hughes, J.J. Gómez +11 more

Y.-K. Wu, L.-M. Duan

Building blocks of quantum computers have been demonstrated in small to intermediate-scale systems. As one of the leading platforms, the trapped ion system has attracted wide attention. A significant challenge in this system is to combine fast high-fidelity gates with scalability and convenience in ion trap fabrication. Here we propose an architecture for large-scale quantum computing with a two-dimensional array of atomic ions trapped at such large distance which is convenient for ion-trap fabrication but usually believed to be unsuitable for quantum computing as the conventional gates would be too slow. Using gate operations far outside of the Lamb–Dicke region, we show that fast and robust entangling gates can be realized in any large ion arrays. The gate operations are intrinsically parallel and robust to thermal noise, which, together with their high speed and scalability of the proposed architecture, makes this approach an attractive one for large-scale quantum computing.

Karan K. Mehta, Alfredo Ricci Vásquez, Carmelo Mordini +6 more

Atomic ions controlled by laser light are among the leading candidates for large scale quantum computing. However operational systems today require vast scaling to reach levels capable of useful computational tasks. The integration of light delivery will be an essential component of this for the trapped-ion approach. I will describe results in which the use of photonics integrated into ion trap chips has allowed us to perform high fidelity two-qubit gates, which are an essential building block for quantum computers. These systems have now been extended to the operation of multiple trap zones, and the creation of novel optical fields for ion trap control while a new generation of chips allowing integration of all required wavelengths as well as optimised light delivery offers further enhancements in performance and scaling.

Chuck Easttom