Nanoscale ‘diamond rings’ provide unconventional giant ‘magnetoresistance’ for the development of new quantum devices

Lately, technological developments have made it doable to create artificial diamonds which have related bodily and chemical properties to pure diamonds. Whereas artificial diamonds are usually not thought of “faux” or “imitation,” they’re typically extra reasonably priced than their pure counterparts, making them a well-liked alternative for individuals who need the fantastic thing about a diamond with out the excessive value. Artificial diamonds are additionally typically extra environmentally pleasant, as they don’t require the identical stage of mining and extraction as pure diamonds.

In its pristine state, diamond is a non-conductive materials, devoid of free electrons or “holes” that may facilitate electrical conduction (Determine 1). Nevertheless, by introducing boron atoms into the diamond crystal lattice, its optical and electrical properties may be considerably altered. Because the focus of boron is elevated, the diamond’s coloration shifts from its attribute clear hue to a fragile shade of blue, whereas its electrical conductivity transforms from an insulator to a semiconductor.

Additional will increase within the boron content material lead to a lustrous blue shade that resembles the sheen of metallic surfaces and finally culminates in a deep, ebony coloration. Such closely boron-doped diamond (BDD) can also be as electrically conducting as some metals, and at low temperatures, displays superconductivity, permitting electrical conduction with no resistance.

Superconducting diamond has drawn nice curiosity resulting from its similarity to high-temperature superconductors, i.e., they’re all doped insulators. Intuitively, in distinction to doped insulators, one would count on conductor to be extra promising in establishing superconductivity, whereas the perfect conductors, i.e., gold and silver, don’t behave as superconductors in any respect.

Two electrons which can be bonded collectively and transfer as a single unit, referred to as Cooper pairs, should work together with and move by means of quite a few grain boundaries throughout the BDD movie. Every grain boundary subsequently acts like a weak hyperlink within the circuit. This offers rise to a collection of unique quantum phenomena, e.g., anomalous superconducting anisotropy and grain-sized dependent electrical transport.

Superconductivity or unconventional big ‘magnetoresistance’ in diamond

Research of superconductivity in varied supplies have established that to ensure that a cloth to turn out to be superconducting, it first must move by means of a metallic state. A longstanding query is whether or not the formation of Cooper pairs in a longtime steel will inevitably remodel the host materials right into a superconductor.

A world staff of scientists led by researchers from Denmark, the U.Ok., China, Japan and Belgium has not too long ago addressed this query by investigating {the electrical} transport in diamond nanorings—loops of superconducting BDD (Determine 2).

Of their research revealed in Superior Supplies, they discovered that beneath the BDD superconducting transition temperature, the diamond nanorings exhibit an abrupt resistance enhance moderately than a resistance drop, suggesting the transformation of the diamond nanorings from metals into bosonic semiconductors.

Together with the bosonic semiconducting transition, they noticed an enormous destructive magnetoresistance that intently resembles the well-known big magnetoresistance (GMR) in magnetic multilayers. In distinction to the traditional GMR originating from spin-dependent scattering, this unconventional big destructive “magnetoresistance” arises from the formation and trapping of Cooper pairs throughout the diamond nanorings. Demonstration of such unique quantum phenomena might open up new paradigms for the event of novel superconducting quantum gadgets.

This story is a part of Science X Dialog, the place researchers can report findings from their revealed analysis articles. Visit this page for details about ScienceX Dialog and take part.