Four, yes, Four possible ways to create invisibility

Quantum conjurers from Imperial College London: Dr Mark Frogley and Prof Chris Phillips

Telegraph:

Next week, a team led by Prof Chris Phillips, a quantum conjurer from Imperial College London, will join an elite coven at the Royal Society's summer exhibition (see below for details), where they will present tantalising evidence of how to make objects disappear. At the flick of a switch, he and his colleague Dr Mark Frogley can make something invisible, albeit just a fraction of a millimetre square of a special material and only for a one ten thousandth of a millionth of a second.

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"As Prof Phillips says, 'we have proved the physics'. Although this was achieved with an idealised material, it suggests that by carefully designing a wand of laser light it may be possible to make anything transparent. 'The effect has the potential to lead to all sorts of new applications. You can imagine a laser that works at frequencies we can't see and, when it shines on your hand, it would open up a transparent hole.'

Called 'dressing' by quantum boffins, coupling can do more than stop materials from absorbing light. Turn up the coupling laser and the light passing through an object is amplified. 'If you made my hand transparent so I could see something the other side, like your face, I could make it appear brighter and brighter,' he says.

The laws of physics predict that something strange occurs at the same time: as the image brightens, there is a dramatic slowing down, by a factor of almost 40, of the speed of light inside the artificial atom. 'This may hold the key to ways of storing and manipulating information in a new and entirely optical way,' says Prof Phillips.

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What is perhaps even more remarkable is that this is one of no fewer than four approaches to invisibility to emerge in the past couple of years. "