Tag Archives: quantum

Quantum superposition breakthrough

theory_actualA rich seam of technological and science-fictional ideas seem ready to be mined with the development of the first light trap that can simultaneously store different numbers of photons:

“These superposition states are a fundamental concept in quantum mechanics, but this is the first time they have been controllably created with light,” Cleland said. Martinis added, “This experiment can be thought of as a quantum digital-to-analog converter.” As digital-to-analog converters are key components in classical communication devices (for example, producing the sound waveforms in cell phones), this experiment might enable more advanced communication protocols for the transmission of quantum information.

The research is funded by IARPA. Intelligence services are understandably keen to learn more about the potential for quantum computers to break conventionally encrypted communications.

[image and story from Physorg]

God of the gaps and the limits of science

thoughtAcademic Jon Taplin highlights this WSJ piece on quantum entanglement and the theories of French physicist Bernard d’Espagnat:

In March, the 87-year-old Frenchman won the prestigious $1.5 million Templeton Prize for years of work affirming “life’s spiritual dimension.”

Based on quantum behavior, Dr. d’Espagnat’s big idea is that science can only probe so far into what is real, and there’s a “veiled reality” that will always elude us.

Many scientists disagree. While Dr. d’Espagnat concedes that he can’t prove his theory, he argues that it’s about the notion of mystery. “The emotions you get from listening to Mozart,” he says, “are like the faint glimpses of ultimate reality we get” from quantum experiments. “I claim nothing more.”

I am not familiar with Prof. d’Espagnat’s work. Is he talking about the God of the gaps or the Popperian problem of induction?

[image from P/\UL on flickr]

Schneier slams quantum crypto as ‘pointless’

bank vault doorSecurity maven Bruce Schneier (who’s an active science fiction fan, by the way) has a column up at Wired that gives quantum cryptography a vigorous kicking. Evidently he’s been noticing the same stories as myself, because he points out that “headlines like the BBC’s “‘Unbreakable’ encryption unveiled” are a bit much.” O RLY?

The big difference between Schneier and me, though, is that he really knows how this stuff all works… and as such, he’s not seduced by quantum cryptography’s golden promises:

Security is a chain; it’s as strong as the weakest link. Mathematical cryptography, as bad as it sometimes is, is the strongest link in most security chains. Our symmetric and public-key algorithms are pretty good, even though they’re not based on much rigorous mathematical theory. The real problems are elsewhere: computer security, network security, user interface and so on.

Let’s not forget the weakest link of all, either – the users themselves… [image by the anonymous collective]

Magnetic currents and efficient memory

Japanese physicists have found something called the Spin Seebeck Effect that could lead to practical magnetic batteries:

Essentially, this spin-segregated rod now has two electrodes and serves as the basis for a new kind of battery that produces “spin voltage,” or magnetic currents, which have been difficult to produce. With this tool, physicists can work toward developing more kinds of spintronics devices that store information magnetically.

Magnetic information storage is inherently more efficient than storing information electronically because there is no waste heat.

This is an interesting development. There seems to be a lot going on in the world of practical applications for quantum dots, quantum cryptography and spintronics. I suspect it will be one of those areas that heralds a lot of unexpected innovation over the next few years and decades.

[image from Ella’s Dad on flickr]

Unbreakable quantum crypto! Or, er… not.

Another frustration of science news-following – the contradictory stories. According to the BBC, a conference in Vienna saw the launch of “the world’s first computer network protected by unbreakable quantum encryption. [Hat tip to Darren ‘Orbit’ Turpin]

Meanwhile, at Trondheim in Norway, another researcher has discovered that quantum cryptography can be hijacked by shining a bright light into the equipment. Someone sort these people out with an RSS reader!