Electrons “synch up” to form superconductors
OXFORD, UK – One hundred years after superconductivity was
first observed in 1911, a team of researchers has used laser light to transform
a nonsuperconducting material into a superconductor.
Superconductivity – a phenomenon in which an electric current
travels through a material without any resistance – allows materials to act
as perfect electrical conductors without any energy loss.
The researchers, from Oxford, Germany and Japan, observed conclusive
signatures of superconductivity after hitting a nonsuperconductor with a strong
burst of laser light. They used a material closely related to high-temperature copper
oxide superconductors for their research, which appears in Science, Vol. 331, No.
6014, pp. 189-191 (2011).
They describe how they used a strong infrared laser pulse to perturb
the position of some of the atoms in the material. The compound, which was held
at a temperature 20° above absolute zero, almost instantaneously became a superconductor
for a fraction of a second, before it relaxed back to its normal state.
They found that the nonsuperconducting and the superconducting
states are not that different in the materials, as it took only a millionth of a
millionth of a second (1 x 10—12) for the nonsuperconducting material’s electrons
to “synch up” and superconduct. The results showed that the nonsuperconducting
material essentially was synched, but that something was preventing it from sliding
around with zero resistance. By using precisely tuned laser light, they removed
the frustration, unlocking its superconductivity.
The researchers hope that the advancements will offer a new route
to obtaining superconductivity at higher temperatures. If superconductors can be
made to work at room temperatures, it could open the door for many technological
- A metal, alloy or compound that loses its electrical resistance at temperatures below a certain transition temperature referred to as Tc. High-temperature superconductors occur near 130 K, while low-temperature superconductors have Tc in the range of 4 to 18 K.
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