THERE is a simple rule of computing that holds true even in the weird quantum world: increase the number of units of information available and you boost computing power. Raising the number of quantum bits, or qubits, carries an even greater reward – every additional qubit doubles the computing power.
But raising the number of qubits has proven tricky because of the difficulty of reliably producing entangled particles. Now a team has designed a system that should fire out barrages of entangled photons with machine-gun regularity.
Existing methods of producing entangled photons tend to spew out photons more or less randomly, says Terry Rudolph at Imperial College London. "People have produced six entangled photons but they come out at times we cannot control," he says. "Ultimately that isn't going to help us build a proper quantum computer."
Rudolph and Netanel Lindner at the Technion-Israel Institute of ...