Control of atomic systems
AtomchipsPrecise control over the internal states of ultracold atoms in arrays of potential wells is a key element for atomtronics applications in quantum information, quantum simulation and atomic microscopy. Here we theoretically study atoms trapped in potential energy landscapes defined by a combination of static, radio-frequency and microwave radiation. We propose schemes for engineering traps with non-trival topologies, and arrays of traps with single site addressing for fast and high-fidelity single-qubit gates with low error due to cross-talk. This work focuses on demonstrating atomic trapping and qubit manipulation relying exclusively on long-wave radiation, suitable for atom-chip technology.
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Spectroscopy of dressed quantum systemsWe study the spectrum of quantum systems dressed by periodic drivings, and analyse experimental results obtained with atomic alkali species. The dressed spectrum consist of several resonant side bands spaced at intervals equal to the dressing frequency, corresponding to transitions enabled by the dressing field. As a proof of concept, we demonstrate how the spectral signal of the dressed system enables an accurate determination of the dressing configuration and the probing field.
G. A. Sinuco-Leon, et al. Phys. Rev. A 100, 053416 (2019) |
Dynamical decouplingWe study the coherence properties of dressed quantum systems (e.g. the hyperfine Zeeman sub-levels of alkali atoms) and engineer combinations of static and AC magnetic fields to modify the response of the quantum transitions to environmental noise. For 87Rb, in collaboration with the experimental group at the IESL-FORTH, we demonstrated the existence of “magic” dressing conditions where the response is minimal. We are interested in finding polychromatic dressing configuration that reduces the global sensitivity of the quDits(quantum systems with D energy states), and enable the simultaneous protection of all possible transitions.
In the figure, we show the typical dependence of several transition frequencies of a quantum system (here 87RB) as a function of an external parameter (here the static field). At the turning points, the transition frequency presents a minimal sensitivity to variations of the parameter. |
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