Quantum Hardware
A new ion trap could make quantum computers possible

Source: “A Microfabricated Surface-Electrode Ion Trap for Scalable Quantum Information Processing”
S. Seidelin et al.
Physical Review Letters 96: 253003

Results: Researchers at the National Institute of Standards and Technology have developed a new device that electromagnetically traps ions. The chiplike trap is easy to make, can be mass produced, and can hold up to 12 ions to be used for quantum computation.

Why it matters: Quantum computers would be able to perform millions of operations simultaneously; in principle, they could break complex encryption codes or search vast databases, tasks that are prohibitively time consuming with current technology. Many researchers believe that a promising way to represent “quantum bits”–the basic units of quantum computation–is to use ions, or charged atoms. The ions are held in place with electromagnetic fields produced by devices called ion traps, and computations are then executed by lasers, which manipulate the behavior of the trapped ions. But most existing ion traps have drawbacks. Those that are easy to make can manipu­late ions in only one trapping zone, which limits their computational power; others that allow for more trapping zones are difficult to mass produce. The NIST trap is the first that could potentially address both problems.

Methods: Using standard microfabrication techniques, the researchers built a trap that has a single layer of gold electrodes; other types of traps have two or three layers of electrodes, making them more difficult to mass produce. The electrodes create an electromagnetic field that isolates magnesium ions and holds them in place 40 micrometers above the trap, where they could be used to perform a computation.

Next steps: The team will continue to explore more-complex traps that hold more ions. Future traps will also have structures that allow the ions to be manipulated with lasers in order to perform logic functions, a key step toward making quantum computers.