These researchers are proposing that aircraft can function more efficiently using superconducting turbines, which are powered by superconducting magnets. I'm not kidding you.
A superconducting magnet, however, would be much more efficient and powerful for its size. When chilled to 77 kelvins (–321 degrees Fahrenheit) or colder, so-called high-temperature superconductors such as the ceramic YBCO (yttrium barium copper oxide) begin to carry electricity without resistance, which produces a strong magnetic field without wasting energy.
Just because YBCO becomes a superconductor at liquid helium temperature does not mean all the problems are solved. It is a Type II superconductors, which means that there will be magnetic vortices migrating all over the place when it is within a magnetic field of sufficient strength. This diminishes it's "zero conductance" property. Furthermore, the reason why these high-Tc superconductors are not used in all those superconducting magnets that are being installed at the LHC is because they can't tolerate high magnetic fields because the low supercurrent density tends to quench superconductivity at sufficiently high fields.
But more importantly, they seem to ignore the fact that (i) you have to carry the cryogenics and (ii) you have to maintain the cryogenics. This adds weight AND require extra power consumption. Did they take this into account when they estimated all of these "efficiency"?
To be fair, I should read the paper they published rather than rely on some silly news report, especially from Sci-Am that lacks any exact citation to it. So I'll try to get a hold of it when see if I will change my mind afterwards.