## Lightning struck twice this year!

Posted by Arjendu on July 21, 2008

My paper with Arik, that went through more rounds of complicated Referee reports than I had previously experienced, got accepted at Physical Review Letters! Who-hoo. (See a previous post about why that’s something worth celebrating.)

I had previously tried to write down what we did in this paper, here’s a newer version. The title is “Non-monotonicity in the quantum-classical transition: Chaos induced by quantum effects”.

Classical (that is, day-to-day) systems can be understood as the limit of quantum system as the system size becomes sufficiently large, such that Planck’s constant is essentially zero. Of these classical systems, it had been understood that some (perhaps many, perhaps most, depending on how you count) classical systems are chaotic and on the other hand, their quantum counterparts are NOT chaotic. This perspective has changed recently when considering so-called ‘open systems’, which accounts for local and random interactions with other nearby systems, termed environmental decoherence — in this case, the quantum system can be chaotic as well. What this paper shows is that in a classical system which is NOT chaotic, as the system size is decreased, chaos can emerge. Thus, quantum effects such as zero-point energy and tunneling are responsible for the chaos. As the system size is increased further, the chaos disappears, providing a striking example of the fact that the behavior of nonlinear systems as a function of parameters can be qualitatively, and not just quantitatively, non-monotonic.

## Nick said

Congrats! Is is there a preprint around we can look at or does PRL have one of those silly exclusivity contracts?

## arjendu said

Here is a preprint (though not the final version). Thanks!