"A magnetic field interacts with gun and the machine detects the reflection," Sanchez said. "One can reduce the reflection because you don't disturb the magnetic field."
Sanchez said before he got to that point, he would consult with authorities on ways to defeat his own theoretical device.
This so-called "anti-magnet" consists of several layers. First would be a layer of superconducting material to stop the magnetic field of an object from leaking outside. That would be covered by outer layers of "metamaterials" which would correct distortions from an outside magnetic field, and thereby make the object appear invisible.
Sanchez said he did this using computer simulations of a cylindral device cloaking a small magnet.
But not everyone is convinced.
MIT professor of materials science Caroline Ross says there are two big problems. First, nobody has been able to make superconducting materials at room temperature. The best right now is 77 degrees Kelvin (or minus 200 C).
"It's quite likely this thing works in a computer, but it's a question of whether it works in real life," Ross said.