Cloaking is surely the zeitgeist topic of the moment and for proof, you need look no further than the work of Jessica Fransson from the University of Upssala in Sweden and colleagues. This is a group who have who have applied the ideas of cloaking to the quantum world and come up trumps. the result is a design for a molecular cloak that could turn out to be extremely useful.
First what does it mean to see or not see a quantum object? Fransson and co say that seeing is equivalent to detecting quantum objects and in the case of molecules that means looking for the terahertz radiation they produced when they vibrate.
“We propose a method for detecting and manipulating quantum invisibility based on THz cloaking of molecular identity in coherent nanostructures,” says Fransson and buddies.
In practice, this means designing quantum corals, elliptical nanostructures, that absorb terahertz waves of specific frequencies. When a molecule that emits this frequency is placed at the focus, it cannot be spotted. It is essentially invisible.
Useful? You bet. Such a quantum coral would be ideally suited to detecting molecules of specific species while ignoring others. For example, if you have a particular molecular species that poisons your measurements, then what you need is a cloak that will make it invisible to your detectors
It’s ideas like this that are going to make cloaking mighty useful one of these days.
Ref: arxiv.org/abs/0811.1782: Quantum Detection and Invisibility in Coherent Nanostructures