
Scientists have built a quantum computer in a diamond, the first of its kind. The chip in the image measures 3mm x 3mm, while the diamond in the center is 1mm x 1mm. (Credit: Courtesy of Delft University of Technology and UC Santa Barbara)
Diamonds are forever — or, at least, the effects of this diamond on quantum computing may be. A team that includes scientists from USC has built a quantum computer in a diamond, the first of its kind to include protection against “decoherence” — noise that prevents the computer from functioning properly.
The demonstration shows the viability of solid-state quantum computers, which — unlike earlier gas- and liquid-state systems — may represent the future of quantum computing because they can be easily scaled up in size. Current quantum computers are typically very small and — though impressive — cannot yet compete with the speed of larger, traditional computers.
The diamond quantum computer system featured two quantum bits (called “qubits”), made of subatomic particles. As opposed to traditional computer bits, which can encode distinctly either a one or a zero, qubits can encode a one and a zero at the same time. This property, called superposition, along with the ability of quantum states to “tunnel” through energy barriers, will some day allow quantum computers to perform optimization calculations much faster than traditional computers.
Like all diamonds, the diamond used by the researchers has impurities — things other than carbon. The more impurities in a diamond, the less attractive it is as a piece of jewelry, because it makes the crystal appear cloudy. The team, however, utilized the impurities themselves. A rogue nitrogen nucleus became the first qubit. In a second flaw sat an electron, which became the second qubit. (Though put more accurately, the “spin” of each of these subatomic particles was used as the qubit.)
via Quantum computer built inside a diamond.
