A couple of diamond-related news items have crossed my path lately causing me to consider diamonds and their social implications. I’ll start first with the news items, according to an April 4, 2012 news item on physorg.com a quantum computer has been built inside a diamond (from the news item),
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.
I last mentioned decoherence in my July 21, 2011 posting about a joint (University of British Columbia, University of California at Santa Barbara and the University of Southern California) project on quantum computing.
According to the April 5, 2012 news item by Robert Perkins for the University of Southern California (USC),
The multinational team included USC professor Daniel Lidar and USC postdoctoral researcher Zhihui Wang, as well as researchers from the Delft University of Technology in the Netherlands, Iowa State University and the University of California, Santa Barbara. The findings were published today in Nature.
The team’s diamond quantum computer system featured two quantum bits, or 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, some day will 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.)
Electrons are smaller than nuclei and perform computations much more quickly, but they also fall victim more quickly to decoherence. A qubit based on a nucleus, which is large, is much more stable but slower.
“A nucleus has a long decoherence time – in the milliseconds. You can think of it as very sluggish,” said Lidar, who holds appointments at the USC Viterbi School of Engineering and the USC Dornsife College of Letters, Arts and Sciences.
Though solid-state computing systems have existed before, this was the first to incorporate decoherence protection – using microwave pulses to continually switch the direction of the electron spin rotation.
“It’s a little like time travel,” Lidar said, because switching the direction of rotation time-reverses the inconsistencies in motion as the qubits move back to their original position.
Here’s an image I downloaded from the USC webpage hosting Perkins’s news item,
I’m not sure what they were trying to illustrate with the image but I thought it would provide an interesting contrast to the video which follows about the world’s first purely diamond ring,
What with the posting about Neal Stephenson and Diamond Age (aka, The Diamond Age Or A Young Lady’s Illustrated Primer; a novel that integrates nanotechnology into a story about the future and ubiquitous diamonds), a quantum computer in a diamond, and this ring, I’ve started to wonder about role diamonds will have in society. Will they be integrated into everyday objects or will they remain objects of desire? My guess is that the diamonds we create by manipulating carbon atoms will be considered everyday items while the ones which have been formed in the bowels of the earth will retain their status.