Novel Superconducting Material Does The Impossible; May Open Up New Possibilities in Solid State Physics

Whether this has the same effect as Silicon had in revolutionising solid state devices is something that only time will tell, but this certainly seems to have a lot of potential. Researchers at the Stanford Institute for Materials and Energy Sciences (SIMES) have been able to synthesize a new material by sandwiching two nonmagnetic insulators together. The wonderful property is that within this substance, both superconductivity and magnetism exist simultaneously.

A Magical Property

Meissner Effect

Superconductors are substances which allow the flow of current almost unhindered, unlike ordinary conductors, which have resistance. The flow is almost 100% efficient. A peculiar property unique to superconductors is that they expel any magnetic field within them by the so-called Meissner Effect. Ordinary spherical conductors allow a uniform non-zero magnetic field within them. One of the signatures of the onset of superconductivity when such a conductor is cooled is the almost sudden drop of this internal field to zero. So, superconductivity and magnetic field are uncomfortable bedfellows.

New Magical Material

In this novel substance, made by strapping together a thin film of lanthanum aluminate on a strontium titanate substrate, both superconductivity and magnetic field exist together at the boundary. At this junction, current flows with no resistance.

Never has it been seen that superconductivity and magnetic fields help each other. The researchers are still to establish the relation in this system. If they assist one another, it will again pose another interesting problem to the already bulging bag of puzzles in superconductivity. Scientists at MIT confirmed that superconductivity and magnetism indeed exist at the boundary.

Looking for more

The SIMES group is looking at the response of the substance to externally applied electric fields, especially alternating ones. They are also looking at how the substance reacts to being compressed. No one knows why superconductivity and magnetism coexist and that too at the boundary of two nonmagnetic non-metallic substances, but they suspect that some new phenomenon might be afoot contributing to both these effects.

There is, indeed, more magic in physical phenomena than in heaven and earth.

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Debjyoti Bardhan

Is a science geek, currently pursuing some sort of a degree (called a PhD) in Physics at TIFR, Mumbai. An enthusiastic but useless amateur photographer, his most favourite activity is simply lazing around. He is interested in all things interesting and scientific.