Individual Addressing with Trapped Yb+ Ions

Recently it has been shown that the simulation of one quantum system by means of observing the dynamics of another suitably tailored quantum system can be experimentally far less demanding than universal quantum computation. A system of pair-wise coupled spins described by a Heisenberg model, or a variant thereof, is particularly useful for quantum simulations that in turn are relevant, for instance, for condensed matter physics. We work on the implementation of a pseudo-spin many-body system that will serve as a well controlled prototype system and will allow for the exploration of quantum simulations: in a particular type of ion trap individual atomic ions interact via an adjustable pseudo-spin-spin coupling and, in addition, each spin is individually accessible, thus providing us with an "ion spin molecule". An important milestone towards realizing such ion spin molecules is the individual addressing of a particular spin employing a spatially varying magnetic field. We demonstrate for the first time individual addressing of ions using radio frequency radiation. Yb⁺ ions are confined in a linear Paul trap and laser cooled such that they form a linear Coulomb crystal. Then, an RF-optical double resonance experiment is performed.