A technical paper titled “Rapid exchange cooling with trapped ions” was published by researchers at Georgia Tech Research Institute.

Abstract:

“The trapped-ion quantum charge-coupled device (QCCD) architecture is a leading candidate for advanced quantum information processing. In current QCCD implementations, imperfect ion transport and anomalous heating can excite ion motion during a calculation. To counteract this, intermediate cooling is necessary to maintain high-fidelity gate performance. Cooling the computational ions sympathetically with ions of another species, a commonly employed strategy, creates a significant runtime bottleneck. Here, we demonstrate a different approach we call exchange cooling. Unlike sympathetic cooling, exchange cooling does not require trapping two different atomic species. The protocol introduces a bank of “coolant” ions which are repeatedly laser cooled. A computational ion can then be cooled by transporting a coolant ion into its proximity. We test this concept experimentally with two ⁴⁰Ca⁺ ions, executing the necessary transport in 107 μs, an order of magnitude faster than typical sympathetic cooling durations. We remove over 96%, and as many as 102(5) quanta, of axial motional energy from the computational ion. We verify that re-cooling the coolant ion does not decohere the computational ion. This approach validates the feasibility of a single-species QCCD processor, capable of fast quantum simulation and computation.”

Find the technical paper here. Published February 2024.  A related news release, including a video, can be found here.

Fallek, S.D., Sandhu, V.S., McGill, R.A. et al. Rapid exchange cooling with trapped ions. Nat Commun 15, 1089 (2024). https://doi.org/10.1038/s41467-024-45232-z

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