Double, Double, Superconductivity, and Trouble

  • By Jenny Stein
  • 15 July 2020

However, there is no "fire burn and cauldron bubble" here because PQI members don't need a magic potion to be double featured in the Nature Physics July Focus editorial highlighting emergent superconductivity. Out of the four articles in this discussion, Sergey Frolov and Jeremy Levy each contributed a perspective on the current status and trajectory of research in superconductivity.   

The perspective from Sergey and collaborators, Topological superconductivity in hybrid devices, details special features found in topological superconductors and emergent properties, such as theorized Majorana quasiparticles and phases. Unambiguously inducing and controlling Majorana phases in superconductors remains a yet to be solved challenge for researchers, but progress has been made. Utilizing the interface between superconducting and semiconducting materials, simulating “spinless” fermions through polarization tricks and improved nanodevice design have elevated experiments and researchers are beginning to eliminate ambiguity/potential imposters in their measurements. Ultimately, Majorana have incredible qualities that allow for everything from applications in quantum computing to the potential for observing more exotic types of superconductivity. 

For those outside the world of superconductivity, “exotic superconductor” might sound weird - it’s already exotic enough as it is! Superconducting magnetic levitation videos are a dollar a dozen, but this lab party trick has a nice and neat explanation- and has for decades. The metal gets cold, the electrons pair up. Working together this pair, known as a “cooper-pair”, can impersonate a boson. This behavior along with the presence of a band gap leads to many of the hallmark traits of superconductivity. But when probing the edges or extremes, some materials enter a state characterized by a pseudogap. Jeremy Levy and collaborators detail materials demonstrating behaviors that don’t seem to be explained by traditional models in their perspective, Pre-formed Cooper pairs in copper oxides and LaAlO3—SrTiO3 heterostructures. They offer a theory (along with a catalog of experimental support) to explain psuedogap behavior: pre-formed Cooper pairs, a state where Cooper pairs are present without superconductive behavior.

Check back later for a more in-depth breakdown of each of these studies!

Written by Erin Fierro