A Practice Science News Article

This was my first introduction to writing a quick science news article that would go into something like the New York Times.  We were supposed to create the article based off a press release and the original paper.  My article was about a small advance toward making quantum computers.  I've already gotten comments from my professor, but more feedback is welcome, from people with and without a science or journalism background .

That’s one small twist for electrons, one ten-second leap for computer technology


Quantum computers would be able to perform 100 billion calculations nearly instantaneously and solve problems in a few months that would take even our fastest computers millions of years.  While scientists have made plenty of theoretical developments regarding quantum advances in engineering such devices have been slow in coming.  But an international team of researchers is now one step closer to a physical quantum computer after developing a new method to control certain properties of electrons.

Scientists Stephen Lyon and Alexei Tyryshkin controlled the electrons in a bar of silicon, cooled to just above absolute zero, by sending pulses of microwaves across the bar, thereby arranging the electrons in an ordered manner.  The orderliness of the electrons is what allows quantum computers to work.  As long as the electrons remain ordered, the computer has access to the information stored in the particles.

Previously, Lyon’s group was able to keep the electrons ordered for about 60 milliseconds.  Using their new method, they were able to maintain order for 10 seconds.  Other researchers have kept electrons ordered for at least hundreds of seconds, but their techniques do not use silicon, which will put them at a disadvantage when it comes time to manufacture the computer parts.

The property that allows information to be stored in electrons is the same property that Lyon and Tyryshkin must control.  This property is known as “spin” and it is a fundamental characteristic of electrons.  Spin can be thought of as the property of electrons that allows each electron to create a small magnetic field.  An electron’s spin can either be “up” or “down”, similar to how standard binary computers use either a 0 or a 1 to encode information.  An electron’s spin can also be in a “superposition”, in which its spin is both up and down.  This superposition has no analog on a macroscopic scale and is what gives quantum computers their incredible computing ability.

The microwaves that the group pulsed across the silicon allowed the researchers to control the electrons’ spin.  “The first pulse twists them, the second reverses them, and at some point the sample itself produces a microwave pulse, and we call that the echo,” Lyon stated in a press release in January.  “By doing the second pulse, getting everything to reverse, we get the electrons into phase.”  While the electrons are “in phase,” the spins of the electrons are coordinated, and the information encoded in the spin of the electrons is accessible for calculations.

Once the spin of the electrons becomes uncoordinated, the information is no longer accessible.  Therefore, developments that allow scientists control over the electrons’ spin for increasingly longer periods of time are absolutely necessary before a quantum computer can be built.  As Tyryshkin puts it, “The bottom line is, you want [coherence] as long as possible.”

Magnetism is one of the ways the electrons can become uncoordinated.  One of the reasons Lyon and Tyryshkin were successful in increasing the time the electrons’ spin remained coherent was because they were able to reduce the magnetism interfering with the electrons in the silicon bar.  Some versions of silicon will produce their own magnetic fields, depending on how the atoms are structured, while some are magnetically silent.  The team had to find the version of silicon that would produce the least magnetism.  This happened to be silicon-28.

Lyon and Tyryshkin purified the silicon so it contained very few contaminants, such as silicon-29, which produces plenty of magnetism.  In fact, they purified their sample so well, that they were worried the sample would not respond to the microwave pulses.  The response the silicon puts out due to the microwaves is how the researchers know the electrons’ spins have become aligned.  To make the sure that the silicon would produce a response to the microwaves, they had to introduce some phosphorus to the sample, a process that took extreme precision.

“A lot of the work boils down to getting the phosphorous far enough apart,” Lyon said.  Too much and the magnetism that will disorder the electrons returns; too little and the sample remains unresponsive to the microwaves and the scientists have no way of knowing how the electrons are reacting.  “It has taken quite a bit of work to get to this point,” Lyon said.  “Nine years of refining measurements and materials.”  Michael Thewalt, a physics professor at Simon Fraser University and Kohei Itoh, a professor at Keio University, helped obtain the necessary amounts of silicon.

The temperature of the silicon also plays a part in reducing magnetic noise.  The silicon was cooled to 2 kelvin (A kelvin is a unit of temperature, like degrees Fahrenheit or degrees Celsius).  For comparison, the vacuum of space is about 3 kelvin, and at 0 kelvin, or absolute zero, all thermal heat vanishes.  The low temperature reduces magnetic activity, which helps keep the electrons ordered, and their information available, longer.

While Lyon and his team have made substantial progress toward making quantum computing a reality (their work was published in Nature Materials in December 2011) by twisting and turning their electrons at their will, extending electron coherence time is only one obstacle delaying the creation of a quantum computer.  Researchers still need to find a way to increase the amount of information that the computer can handle at one time.

Currently, Lyon and Tyryshkin have the equivalent of one “qubit” of information.  A qubit is the smallest unit of information a quantum computer could deal with, similar to a 0 or a 1 for a regular computer.  Tyryshkin explained that future computers will need to control and access many more qubits.  “Right now, we are using one,” he said.  “If we could come up with a thousand, that would be a very interesting machine.”

Scientists have yet to determine how many qubits are necessary and how long the electrons would have to remain coordinated in order to create a functional quantum computer.  But when all the pieces of research and engineering finally come together, it will signal a computing revolution.