The Quantum Pontiff

A What Bit?

A correspondent writes to me about a recent article in the APS News describingThe Top Ten Physics Stories of 2008 and notes a very troubling sentence:

Diamond Detectors
Work on the molecular structure of carbon continues to show great promise for quantum computing. This year scientists were able to construct a nano-scale light source that emits a single photon at a time. The team first removed a solitary atom from the carbon’s otherwise regular matrix and then introduced a nitrogen atom nearby. When they excited this crystal with a laser, single polarized photons were emitted from the empty space. These photons could be used to detect very small magnetic forces. Additionally the photons emitted contained two spin states and were able to exist in that state for nearly a millisecond before their wave function collapsed. The emitted photon is essentially a long-lasting qbit which could, with further development, be entangled with other adjacent qbits for uses in quantum computing. Another team at the University of Delft in the Netherlands, working in conjunction with UCSB, was able to detect the spin of a single electron in a diamond environment. At the same time, a group at Harvard was able to locate within a nanometer a single Carbon-11 impurity using its nuclear spin interactions.

Qbit? What’s a qbit? Doh.

Comments

  1. #1 Ian Durham
    February 16, 2009

    Ask David Mermin. He’ll tell you all about Qbits.

  2. #2 Jonathan Vos Post
    February 17, 2009

    WHBIT: suggested abbreviation for “A What Bit?”, likely to be a common question as bad science reporters imitate each other (silly bosons that they are).

    Of course, this raises the question of the No Bozo Cloning Theorem.

  3. #3 Anonymous Coward
    February 17, 2009

    I was distracted from the spelling issues by the description of a photon as a long-lasting q(u)bit. I’m dumbfounded by the article’s implication that an EMITTED photon has a coherence time in the millisecond range. Is that possible? (Aside from the French superconducting microwave cavities.)

    Or it it just a hairy description of some atomic (nitrogen vacancy) state which has a millisecond coherence time and whose information be coherently converted, on demand, into a photon?