Three-dimensional micro-electromagnet traps for neutral and charged   particles
  Three-dimensional (3D) micro-electromagnets were developed to control particle motion in magnetic field landscapes in vacuum near a chip. Multiple layers of micron-scale conductors separated by transparent insulators create particle containers with deep, symmetric and time-dependent potentials, suitable for integration in quantum circuits. Single and coupled multiple 3D traps, integrated 3D traps with a mirror, 3D guides for neutral particles with spin, and traps for electrons in vacuum are described. 
M. Drndic, C.S. Lee and R.M. Westervelt (Dept. of Physics, Harvard   University)