Saturday, February 17, 2007

This week in cond-mat

Several papers caught my eye this week; I'll be brief, particularly since I haven't had time to read them in detail. Now that our paper is in and our search is nearing the end, I'll have more time soon. Maybe I'll even get time to work on my book. Anyway....

cond-mat/0702246 - Capelle et al., Energy gaps and interaction blockade in confined quantum systems
The authors consider the general problem of interacting quantum particles confined in a harmonic potential. This could apply to electrons in a small quantum dot, or cold atoms in a magneto-optic trap. They then come up with expressions for the addition energies (how much energy is needed to add one more particle to the confined, interacting system) based on single-particle properties plus the interactions. They predict phenomena analogous to Coulomb blockade for other interacting systems, including some kind of Van der Waals blockade for trapped atoms.

cond-mat/0702259 - Kornyushin, An introduction to the polaron and bipolaron theoretical concepts
This looks like a nice pedagogical derivation of polarons and bipolarons. Should be good for students.

cond-mat/0702332 - Wu et al., Shot noise with interaction effects in single walled carbon nanotubes
This is a typically nice piece of experimental work from the Helsinki group. They've measured shot noise in carbon nanotube devices, and while they have seen interesting quantum coherence effects (Fabry-Perot electronic resonances as have been observed in dc conduction in these systems), they do not see any clear signs of Luttinger liquid physics.

cond-mat/0702348 - Phillips, Mottness
This is a longer article by Phil Phillips on his ideas about the properties and excitations of Mott insulators - materials that are insulating not because their bands are all full, but because strong electron-electron interactions lock the carriers in place. Interesting ideas explained in a compelling way, though theorists have been arguing about this stuff (in particular, the role or lack thereof of Mott physics in, e.g., the normal state of the high Tc compounds) for some time. Prof. Phillips is also the best dressed scientist I've ever met, bar none.

8 comments:

Chad R said...

I'm sure the book you mentioned you're working on is a textbook, but it's somehow much more amusing to imagine you're writing a children's book about a jolly sea elephant who learns the true meaning of friendship. That or a Star Trek novel. Come to think of it, I'd definitely read a Star Trek novel you wrote.

Doug Natelson said...

Damnit, Chad, I'm a (science) doctor, not a novelist. As fun as a Trek novel could be, that universe is pretty well mined out. I actually have a couple of mystery novel ideas kicking around - more like clever setups than well-rounded stories with actual characters and solutions.

Dan M said...

a jolly sea elephant? I'd buy the book just to find out what that is...

smm said...

off topic, but...did you see the Room-T QHE in Graphene paper? http://arxiv.org/abs/cond-mat/0702408

the hits keep coming for graphene!

Doug Natelson said...

smm - I have a sense that the politics behind that paper may actually be more interesting than the result itself. I saw data on this months ago at a conference. I gather that there was a lot of maneuvering about how to publish this in a way that gives everyone maximal favorable coverage (e.g. the two generally competing graphene groups of Kim and Geim, plus the National High Magnetic Field Lab, plus the Dutch high field facility).

smm said...

thanks for the insight. as a newcomer to a new field it's a little hard for me to tell. which is why i like your blog!

eliecartan said...

Hi Doug,
Do you know the status of Goldhaber-Gordon's two-channel Kondo effect paper? I thought it would appear in Science or Nature sometime however it is still sitting idly in arxiv. I am talking about cond-mat/0610721.

Doug Natelson said...

ElieCartan - For other reasons I spoke with David earlier this week, and he told me that it's coming out in Nature in two weeks.