“Atom chips” getting better

All chips are made out of atoms, but only recently special chips have been made to guide the motion of (ultracold) atoms. These then are called “atom chips”. A bunch of current-carrying wires on the chip is used to create magnetic fields that determine the potential which the atoms see. In this way, complicated interference setups and other structures can be created – in principle. Up to now, many imperfections have still somewhat slowed progress.

That’s why a recent paper by the Schmiedmayer group,

Designing potentials by sculpturing wires

seems to be an important step forward. They show how they can shape their wires much more accurately than before, which bodes well for the future ability to implement all kinds of nice structures in which transport of ultracold atoms will be studied.

Incidentally, this paper also has the honour of being the first that is linked to on this blog (because it happened to be the first that caught my eye on this day’s cond-mat new articles in arXiv).



As the physicists among you know, the primary resource for the working physicist today, regarding the most recent developments, is the online


with over 300.000 online articles, free for anyone to read (though most admittedly of very limited use for the general non-expert audience). The reason this blog was created is actually the recent introduction of a “trackback” feature to the arXiv, see

Trackbacks on arXiv

I hope to explore the use of this feature, to attach comments to articles published on arXiv. Let’s see whether it works as simple as announced.

Quantum mechanics in Wikipedia

The free online encyclopedia has quite a few articles dealing with quantum mechanics. As an example, have a look at the description of the hydrogen atom:

Hydrogen atom in Wikipedia

Incidentally, the picture of the orbitals was created by myself, a long time ago. It is amazing to see how much the page has changed since then. With pictures that is no problem (they usually stay intact as a whole), but with content that’s another story. I have mixed feelings about Wikipedia (and currently do not contribute any more), since the content can so easily be degraded by some (potentially well-meaning) incompetent beginner (sorry to be so blunt).

That being said, Wikipedia is still a great resource (if used with care) and an amazing phenomenon!

“Quantum coherence” debuts

Why would you want to read this blog?

Suppose you are a physicist (like me) and could use some regularly updated pointers to the most recent literature on all topics dealing with quantum systems, coherence and decoherence, the physics of nanoscale structures, you name it. Suppose besides those links you would even encounter some more or less “coherent” comments and opinions on those articles and how they fit into the general context.

Then this blog might be for you. In any case, I started it after reading about the new trackback feature on the arXiv. Let’s see how this blog works out.