Physicists Find New Way to Store Quantum Information in Impure Diamonds

What’s the News: Physicists have worked out a new method of storing information in the quantum states of atoms in diamond crystals. The scientists linked the spin of individual nitrogen atoms in the diamond—impurities at the jewelry counter, but boons in the physics lab—to the spin of nearby electrons. They could form a quantum link between the spin of the nitrogen atom and the spin of a nearby electron, letting the electron store information more stably than if it were spinning on its own.

How the Heck:

• When a nitrogen is next to an empty spot in a diamond’s carbon framework, it lets off an extra electron, leaving that electron free to have its quantum played around with.
• Using what they call “intense microwave fields” [PDF], the physicists were able to link the spin of a nitrogen atom to a neighboring electron, a pairing sparked by magnetic fields.

What’s the Context:

• Scientists have been looking at diamonds—with and without nitrogen impurities—as a quantum computing material for several years, in part because it can store quantum memory at room temperature, not the far-below-freezing temps required by some other materials.
• Some have even proposed the idea of diamond supercomputers, which would store millions of times as much data as today’s machines.
• One hurdle in quantum computing is getting the information to last long enough to use it. In the recent study, the nuclear spin stayed coherent for more than a millisecond—enough time for a ten petaflop supercomputer to do ten trillion operations.

Not so Fast:

• Don’t start rooting around in your hard drive for a rock just yet; diamond-based quantum computing is still a long way off.

Reference: “Quantum control and nanoscale placement of single spins in diamond.” David D. Awschalom, invited talk, American Physical Society March Meeting 2011

Image: Flickr / Swamibu