Boulder, CO, June 17, 2004--Physicists at the National Institute of Standards and Technology (NIST; Boulder, CO) have demonstrated "teleportation" by transferring key properties of one atom to another atom without using any physical link, according to results reported in the June 17 issue of the journal Nature.
The NIST experiments used laser beam manipulations to transfer quantum states of one beryllium atom to another atom within a set of microscale traps, with a 78% success rate. The technique may prove useful for transporting information in quantum computers of the future, which could use central processing elements smaller than a cube of sugar to carry out massively complex computations that are currently impossible.
The NIST group previously has demonstrated the building blocks for a quantum computer based on atomic-ion traps. The new experiments, which are computer controlled and perform teleportation in about 4 milliseconds, incorporate most of the features required for large-scale information processing systems using ion traps. In addition, the experiments are relatively simple in design and could be used as part of a series of logical operations needed for practical computing.
The demonstration described in the Nature paper exploited quantum properties that are radically different from the properties observed in the "normal" world. For example, ions can be manipulated into a special state known as a "superposition" in which they literally can be in two places at once. Similarly, they also can hold information representing more than one number at once, a common property of all qubits. Ions also can be "entangled" with each other, so that their behavior is related in predictable ways, as if they were connected by an invisible force. Einstein called this "spooky action at a distance."
The NIST work and other research by the University of Innsbruck (Austria) reported in the same issue of Nature mark the first demonstrations of teleportation using atoms. Systems using atoms are arguably the leading candidate for storing and processing data in quantum computers.