Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not a subscriber? Subscribe now for unlimited access to online articles.

Emerging Technology from the arXiv

A View from Emerging Technology from the arXiv

The Puzzle of Superconducting LEDs Explained

Superconducting LEDs are brighter than anyone could explain. Until now.

  • May 12, 2009

It makes intuitive sense that if superconductors can carry currents with zero resistance, then superconducting light emitting diodes might do their stuff with equally amazing efficiency.

But superconducting LEDs are not only bright, they are brighter than anyone can explain, even after taking superconductivity into account. Now a team of Japanese theorists seems to have figured out the puzzle.

The mystery began last year when Japanese researchers built a device to study the way in which Cooper pairs in superconducting niobium would emit light when combining with holes generated in a PN junction. To their surprise, the researchers found that their superconducting LED was not only bright but outshone their expectations by an order of magnitude. What on Earth was going on?

Now Yasuhiro Asano at Hokkaido University in Japan and a few buddies say that the effect can be explained by two peculiar second order effects that occur together only in superconductors. The so-called “giant oscillator strength” and a resonant effect both allow much higher numbers of Cooper pairs than expected to combine with holes and produce photons. This explains the result, say Asano and co.

This is exciting not just because superconducting LEDs will be bright but because Cooper pairs can also produce entangled pairs of photons. That raises the prospect of intense sources of entangled pairs, the likes of which physicists have not yet seen. And that could be hugely useful for everything from quantum communication to quantum teleportation.

Ref: arxiv.org/abs/0905.1182: Luminescence of a Cooper Pair

Keep up with the latest in sustainable energy at EmTech MIT.
Discover where tech, business, and culture converge.

September 17-19, 2019
MIT Media Lab

Register now
More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe to MIT Technology Review.
  • Print + All Access Digital {! insider.prices.print_digital !}* Best Value

    {! insider.display.menuOptionsLabel !}

    The best of MIT Technology Review in print and online, plus unlimited access to our online archive, an ad-free web experience, discounts to MIT Technology Review events, and The Download delivered to your email in-box each weekday.

    See details+

    12-month subscription

    Unlimited access to all our daily online news and feature stories

    6 bi-monthly issues of print + digital magazine

    10% discount to MIT Technology Review events

    Access to entire PDF magazine archive dating back to 1899

    Ad-free website experience

    The Download: newsletter delivery each weekday to your inbox

    The MIT Technology Review App

  • All Access Digital {! insider.prices.digital !}*

    {! insider.display.menuOptionsLabel !}

    The digital magazine, plus unlimited site access, our online archive, and The Download delivered to your email in-box each weekday.

    See details+

    12-month subscription

    Unlimited access to all our daily online news and feature stories

    Digital magazine (6 bi-monthly issues)

    Access to entire PDF magazine archive dating back to 1899

    The Download: newsletter delivery each weekday to your inbox

  • Print Subscription {! insider.prices.print_only !}*

    {! insider.display.menuOptionsLabel !}

    Six print issues per year plus The Download delivered to your email in-box each weekday.

    See details+

    12-month subscription

    Print magazine (6 bi-monthly issues)

    The Download: newsletter delivery each weekday to your inbox

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.