Measurement-Induced Vibrational Dynamics of a Trapped Ion

Control of dynamical localization by an additional quantum degree of freedom

“…We consider the standard Paul trap set-up realized experimentally in many labs [13][14][15]: a standing electromagnetic wave of frequency ω L and wave number k aligned along the x-axis couples the internal states |g and |e of a single two-level ion of mass m to the centerof-mass motion. The resulting dynamics of the ion follows from the time-dependent Schrödinger equation with the Hamiltoniañ…”

Evolution of an Atom Impeded by Measurement: The Quantum Zeno Effect

“…Since then, repeated measurem ents on an individual and iden tically prepared quantum system are indeed avail able. Not only that such a system may serve as an ultra-precise frequency standard [3] or as a build ing block for logical gates in quantum information processing [4]: The entire concept of individual m ea surements on such a system deserves reconsideration [5,6]. Here, unlike with an ensemble o f quantum sys tems, the micro-state of the individual system is re vealed with a measurem ent, and from the eigenvalues that show up as the results, correlations may be de rived up to an order only limited by the num ber of se quential measurem ents in a time series.…”

Does an onlooker stop an evolving quantum system?

“…In fact, another ion being "dark" resided at the location imaged on the lower right part of the Figure. This ion decayed to the ground state and took up scattering probe light again a few milliseconds after the image had been recorded. During the past years, individual ions of barium and ytterbium have been prepared in the outlined way at Hamburg University in order to study the interaction of these ions with light and radio frequency radiation [38][39][40][41][42][43]. Some of this work was devoted to the problem addressed here, i.e.…”