NEVER mind what quantum computers might look like: how on earth do you wire the things up? It鈥檚 a serious problem for the scientists trying to build them. But now Boris Blinov and colleagues at the University of Michigan, Ann Arbor, have found a solution.
In their scheme, each of the computer鈥檚 quantum bits or qubits of information is stored in the energy state of an ion. This design has already proved its worth, and a simple one-ion version is up and running. But making a more powerful quantum computer means using more ions, and finding some way to wire them together.
Blinov has discovered that hitting the ion with a laser pulse made it emit a photon carrying an exact copy of the qubit鈥檚 information. If the information in the photon is manipulated, this change is transmitted back to the ion (Nature, vol 428, p 153). The laws of quantum physics effectively 鈥渨ire鈥� the photon to the ion, so distant ions could interact by sending each other photons 鈥� although the team has yet to try this.
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鈥淭his is a remarkable achievement,鈥� says Peter Knight, an expert in quantum optics at Imperial College London.