Speaker
Description
Deterministic preparation and reconstruction of high-energy Fock states have potential applications in quantum metrology [1], computing [2], simulation [3], and the study of fundamental physics. In trapped ions, common methods to characterise an arbitrary Fock distribution employ first-order sideband interactions [4] of the Jaynes-Cummings type, causing them to fail at high energies due to the Rabi frequency degeneracies in that regime. Hence, reliable Fock reconstruction beyond the Lamb-Dicke limit remains an open question. Here, we present a protocol to overcome this by generalising the driving interactions to any order and using composite pulses that implement narrow-passband filters [5] in rabi-frequency-space. We experimentally demonstrated the protocol in a Paul trap by preparing large Fock states (N > 100) and reconstructing them with high fidelity.
[1] X. Deng et al., Nat. Phys. 20, 1874–1880 (2024)
[2] D. Gottesman et al., Phys. Rev. A 64, 012310 (2001)
[3] R. J. MacDonell et al., Chem. Sci. 12, 9794 (2021)
[4] D. Leibfried et al., Phys. Rev. Lett. 77, 4281 (1996)
[5] B. T. Torosov et al., Phys. Rev. A 92 (2015)
| Academic level | PhD student |
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