Ion trap in a semiconductor chip

The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling¹ and Bose–Einstein condensation of cold gases² to the precise quantum control of individual atomic ions³. Work on miniaturizing electromagnetic traps to the micrometre scale promises even higher levels of control and reliability⁴. Compared with 'chip traps' for confining neutral atoms^5,6,7, 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 arrays⁸, compact atomic clocks⁹ 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 ¹¹¹Cd⁺ ion in an integrated radiofrequency trap etched from a doped gallium-arsenide heterostructure.