This was previously thought to be impossible

Aug 1, 2009 00:11 GMT  ·  By
The new experiments have been performed in Cambridge's Cavendish Laboratory with theoretical support from scientists at the University of Birmingham's School of Physics and Astronomy
   The new experiments have been performed in Cambridge's Cavendish Laboratory with theoretical support from scientists at the University of Birmingham's School of Physics and Astronomy

Experts from the Universities of Cambridge and Birmingham recently discovered that electrons could, indeed, be split into further divisions, in spite of established knowledge. In their experiments, the scientists showed that electrons crowded into narrow wires actually split into particles known as spinons and holons. The find could have far-reaching consequences, seeing how electrons are the particles responsible for carrying electricity and for generating magnetism.

The major find that the UK research team made was that electrons did not exhibit the same properties in groups that they showed when they were studied alone. They have to avoid getting too close to each other, as they all have the same charge. As a result, when crammed together in very narrow wires, they need to modify their trajectories to accomplish this objective. In their natural states, inside metals or other chemicals, there is no need for electrons to engage in this behavior, but it's unavoidable when they are artificially packed together.

The split of electrons under such conditions has been theorized since 1981, by physicist Duncan Haldane. He argued that, when electrons would be stuck inside a narrow wire, and subjected to very low temperatures, they would need to change their properties and separate into two new types of particles called spinons and holons. The experiments required to make these assessments were very complex. The team used quantum wires for the job, which were set very close to a cloud of electrons existing freely. They hypothesized that the electrons would jump from the cloud to the wire via a process called quantum tunneling, which is the basic principle behind the scanning tunneling microscope.

“We had to develop the technology to pass a current between a wire and a sheet only 30 atomic widths apart. Quantum wires are widely used to connect up quantum 'dots,' which may in the future form the basis of a new type of computer, called a quantum computer. Thus understanding their properties may be important for such quantum technologies, as well as helping to develop more complete theories of superconductivity and conduction in solids in general. This could lead to a new computer revolution,” University of Cambridge Cavendish Laboratory expert Dr. Chris Ford explains.

“The experiment to test this is based on an idea I had together with three colleagues almost 10 years ago. At that time the technology required to implement the experiment was still a long way off. What is remarkable about this new experiment is not just the clarity of the observation of the spinon and holon, which confirms some earlier studies, but that the spinon and holon are seen well beyond the region that Duncan Haldane originally conjectured,” University of Birmingham School of Physics and Astronomy scientist professor Andy Schofield adds.

“Our ability to control the behavior of a single electron is responsible for the semiconductor revolution which has led to cheaper computers, iPods and more. Whether we will be able to control these new particles as successfully as we have the single electron remains to be seen. What it does reveal is that bringing electrons together can lead to new properties and even new particles,” he concludes.