Switchable Ion Crystals ⚡ экспресс
Isomerization was studied in a two-dimensional Coulomb crystal of six 138Ba+ ions in a harmonic trap. By continuously tuning the aspect ratio of the potential (analogous to an electron orbital), the potential energy surface (PES) was reshaped, triggering controlled transitions between two stable configurations. A bistability region was experimentally identified; isomerization was detected in real time via configuration-resolved imaging. The crystal temperature was estimated using Monte Carlo simulations of the double-well PES, comparing calculated transition rates with measured populations. Rapid quenching of the PES created metastable states, with switching dynamics resolved with sub-millisecond precision. This work establishes the ion crystal as a platform for emulating molecular processes, opening avenues for studying quantum superpositions of configurations and controlling isomeric excitations.
A tiny crystal of six charged barium atoms behaves like a snap bracelet: it can freeze into one of two shapes. Scientists, watching the glow of the ions (photometry), knew exactly which shape the crystal had taken. By smoothly deforming the trap — as if squeezing or straightening a bracelet — they switched the ions between states. At a critical point, both shapes coexist, and the switches become random, like a spring trembling. Counting the jump frequency, the researchers measured the temperature: the hotter the ions, the faster they ‘snap’, because the disorder grows. The climax: rapid cooling of the trap, freezing the ions right at the moment of transition. For the first time, they caught the intermediate state and watched how the crystal relaxed. This trick gives scientists switchable ‘ion molecules’ for quantum simulations.
🎯 The quality of gasoline depends on the shape of molecules: of the 18 isomers of octane, some burn smoothly, others cause knocking. The engine literally feels the difference between atomic rearrangements.