The effect of instantaneous spectral diffusion (ISD) on gate operations in rare-earth-ion-doped crystals is an important question to answer for the future of rare-earth quantum computing. Here we present a microscopic modeling that highlights the stochastic nature of the phenomenon and use it to investigate ISD errors on single-qubit gate operations. Furthermore, we present a method to estimate the total error from many different error sources by only studying subsystems containing one error source at a time. This allows us to estimate the total ISD error from all nonqubit dopants in the vicinity of a qubit. We conclude that optical pumping techniques must be used to empty the frequency regions around the qubit transitions from absorption (transmission windows) in order to suppress the ISD errors. Despite using such windows, there remains a roughly 0.3% risk that a qubit has an ISD error larger than the error from other sources. In those cases, the qubit can be discarded and its frequency channel can be reused by another qubit. However, in most cases the ISD errors are significantly smaller than other errors, thus opening up the possibility to perform noisy intermediate-scale quantum (NISQ) algorithms despite ISD being present.
|Tidskrift||Physical Review A|
|Status||Published - 2022 mars|
Bibliografisk informationFunding Information:
We want to thank Philippe Goldner for his input on the spectral and crystal site discussion in Appendix . This research was supported by Swedish Research Council (Grants No. 2016-05121, No. 2015-03989, No. 2016-04375, and No. 2019-04949), the Knut and Alice Wallenberg Foundation (Grant No. KAW 2016.0081), the Wallenberg Center for Quantum Technology (WACQT) funded by the Knut and Alice Wallenberg Foundation (Grant No. KAW 2017.0449), and has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 820391 (SQUARE).
© 2022 authors. Published by the American Physical Society.
- Atom- och molekylfysik och optik