Nonlinear measurements - HUP violation or not?

[espen180]

According to this article, researchers have obtained measurements with an accuracy larger than the upper bound set by HUP.

http://physicsworld.com/cws/article/news/45535

a group [...] predicted that the Heisenberg limit could be beaten by introducing nonlinear interactions between the measuring particles. That prediction has now been shown to be true, thanks to an experiment ...

My first thought is that this is not a violation, since we are talking about a finite number of measurements, but then again, I have never heard the term "nonlinear measurement" before.

Any comments are appreciated.

 

[Truecrimson]

I don't know much about it, but my reaction is that the Heisenberg limit might not be the same as HUP.

The original paper that the article refers to can be found http://prl.aps.org/abstract/PRL/v98/i9/e090401" )