Ion trap in a semiconductor chip

The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling(1) and Bose-Einstein condensation of cold gases(2) to the precise quantum control of individual atomic ions(3). Work on miniaturizing electromagnetic traps to the micrometre scale promises even higher levels of control and reliability(4). Compared with 'chip traps' for confining neutral atoms(5-7), ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass-spectrometer arrays(8), compact atomic clocks(9) and, most notably, large-scale quantum information processors(10,11). Here we report the operation of a micrometre-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool and measure heating of a single Cd-111(+) ion in an integrated radiofrequency trap etched from a doped gallium-arsenide heterostructure.