Quantum Entanglement Progresses-March 2009 SIN, Orion

According to a new study published on February 17, 2009, atomic energy levels, called clock states, are “strong contenders” for use in the quantum computer field, possibly leading to faster, and more efficient computing. This information was presented at physics.aps.org. The article, written by David Voss, documents the work of G. Kirchmair, et al.

There are many difficulties with quantum information storage and processing, including writing to, storing, and reading the states. This all must be done with minimal data loss. One theoretical way to do this is by using the more precise optical entanglement method to write the information, and then transfer that to the longer-lasting clock state entanglement.

The researchers showed optically entangled qubits can be transferred to a calcium ion with only slightly over 3 percent data loss. The calcium ion was 43Ca+. The researchers used laser and microwave forces to produce the optical entanglement in two ions, and transferred the entanglement to hyperfine clock state levels with laser pulses. In an optical entanglement, 25 percent information loss is recorded after 3.43 milliseconds; however, with clock state entanglement, information loss of only 3.3 percent is maintained after 96 milliseconds, with longer times perhaps possible.

This may be the next step toward a functional quantum computer. A quantum computer would be able to operate at much higher speeds, with greater efficiency then present computers.