Ion Trap Quantum Computer Papers

Interesting papers in experimental ion trap quantum computation:
Creation of a six-atom ‘Schrödinger cat’ state from Wineland’s group at NIST Boulder, Nature 438, 639-642 (1 December 2005.) Schrodinger’s cat is now six qubits big! And growing! What a cute little kitten.
Scalable multiparticle entanglement of trapped ions from Blatt’s group in Innsbruck. Nature 438, 643-646 (1 December 2005.) In this paper the group discusses experiment they performed which created the so-called “W” entangled state for up to eight qubits. That’s a quantum byte, peoples! Amazingly the group performs full state tomography on these states. Wow that sounds like an awful lot of graduate student hours.

9 Replies to “Ion Trap Quantum Computer Papers”

  1. Didn’t the same group publish some high-impact, highly celebrated publication about 5 atoms last year?
    Excuse my scepticism, but doesn’t seem like a huge breakthrough to me. What’s next – Nature paper in 2006 about 7 entangled atoms, and so on? It seems like for quantum computer to succeed some time in our lifetimes they should be improving at a much faster rates.
    Also, can someone inform us on whether cooling and trapping can become practically available “in a box” – in other words, seems like 10 years after BEC was created, it still requires tremendous effort of grad students, money and expertise to do an incrementally improved version of the same experiment.
    I am sure someone will point out it was the same way with first transistors, first computers and first lasers, but I think there’s a difference here

  2. I don’t know the exact number of grad students hours that were used in the Innsbruck experiment but I might be able to find out…
    What would be more interesting would be the number of cans of coke (actually I think it’s a Pepsi machine that they have outside their lab), number of coffee’s, chocolate bars, relationships, and schnizel’s consumed throughout the course of the experiment.
    Do you think we should talk about complexity of an experiment in terms of grams of caffeine?

  3. Slacker: I will note that 8 is nearly double 5, and, as you state, in a timespan of a year. This is faster or about on target with Moore’s law 😉 BTW…
    “Also, can someone inform us on whether cooling and trapping can become practically available “in a box” – in other words, seems like 10 years after BEC was created, it still requires tremendous effort of grad students, money and expertise to do an incrementally improved version of the same experiment.”
    I believe the status of trapping ions is that it is much eaiser to do these days, but are there turnkey technologies out there? Not that I know about. I also think there are some exciting experiments coming up, however, which are working on exactly this problem (which is why measuring quantum computing progress in terms of number of qubits is a fishy metric.) Also there has been progress on other important fronts: moving ions in segmented traps and performing teleportation, for example, is a big step in the right direction. Sure it doesn’t require the eight qubits, but achieving this step is a big step in the right direction.
    ” am sure someone will point out it was the same way with first transistors, first computers and first lasers, but I think there’s a difference here”
    What is the difference? It took 15 years from Alan Turings paper to the invention of the transistor. Then there is another 10 years to the invention of the integrated circuit. Another 10 years for real commericial integrated circuits. The invention of the laser to the invention of the CD took many years. Technology is damn hard. Of course we don’t know how hard quantum computing really is, so really I’m just talking out of my butt now.

  4. Is distributed quantum computing allows more qubits to be entangled than the trapped ions schemes? I read this paper and this one and think they are every promising.

  5. Dave, you are right, after posting I was feeling the same way. I guess to some degree I was playing devils advocate type argument.
    But sometimes I do feel that AMO stuff should be happening faster. Maybe I am just impatient. I want that quantum computer for Xmas, dammit!

  6. I’m sure that the NIST people would have preferred to go from 5 qubits to 100 qubits over the last year instead of going from 5 to 6. What is it that is holding them back? Is a 100 qubit ion trap quantum computer even feasible, and if so, within what time frame?

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