Monday, June 26, 2017

Lab::Measurement 3.550 released - port to Dist::Zilla

With the release of Lab::Measurement 3.550 we've switched to Dist::Zilla as maintenance tool. If you're not involved in hacking Lab::Measurement, you should essentially not notice this change. However, for the authors of the package, Dist::Zilla makes it much easier to keep track of dependencies, prepare new releases, and eventually also improve and unify the documentation... At the side we've also fixed Issue 4 and Lab::Measurement should now work out of the box with recent Gnuplot on Windows again.

Monday, June 12, 2017

Lab::Measurement 3.544 released - support for Zurich Instruments devices

I've just uploaded Lab::Measurement 3.544 to CPAN. This is our first release containing support for Zurich Instruments equipment, in particular the ZI MFLI digital lock-in amplifier, via Simon's Lab::Zhinst package. Enjoy!

Monday, May 8, 2017

Upcoming talk in the Regensburg physics colloquium

If you're in Regensburg, please come to the physics colloquium next week (15.5., 16:00st, lecture hall H34)! See the linked PDF for the full talk announcement.

"Millikelvin transport experiments on carbon nanotubes - nanoelectromechanics, spectroscopy, and more"

Saturday, March 25, 2017

Testers wanted for Gentoo Perl 5.24.1 stabilization

We want to stabilize Perl 5.24 on Gentoo pretty soon (meaning in a few weeks), and do actually not expect any big surprises there. If you are running a stable installation, are willing to do some testing, and are familiar with our Gentoo bugzilla and with filing bug reports, then you might just be the right volunteer to give it a try in advance!

Here's what to do:

Step 1: Update app-admin/perl-cleaner to current ~arch.
I'm deliberately not supplying any version number here, since I might do another release, but you should at least have perl-cleaner-2.25.

Step 2: Make sure your system is uptodate (emerge -uDNav world) and do a depclean step (emerge --depclean --ask).

Step 3: Download the current stabilization list from bug 604602 and place it into your /etc/portage/package.keywords or /etc/portage/package.accept_keywords.

Step 4: Update your world (emerge -uDNav world), which triggers the perl update and the module rebuild.

Step 5: Run "perl-cleaner --all"  (you might also want to try "perl-cleaner --all --delete-leftovers").

... and make sure you file bugs for any problems you encounter, during the update and afterwards! Feedback is also appreciated if all goes fine; then you best leave a comment here on the blog post.

Tuesday, March 14, 2017

Lab::Measurement at the DPG Spring Meeting Dresden 2017

As nearly every year we'll present a poster on Lab::Measurement at the spring meeting of the German Physical Society again. This time the conference is in Dresden - so visit us on upcoming 23 March 2017, 15:00-19:00, poster session TT75, poster TT75.7!

Thursday, February 9, 2017

Gentoo LiveDVD "Crispy Belgian Waffle", FOSDEM 2017 edition

So, FOSDEM 2017 is over, and as every year it was both fun and interesting. There will for sure be more blog posts, e.g., with photographs from talks by our developers, the booth, the annual Gentoo dinner, or (obviously) the beer event. The Gentoo booth, centrally located just opposite to KDE and Gnome and directly next to CoreOS, was quite popular; it's always great to hear from all the enthusiastic Gentoo fans. Many visitors also prepared, compiled, and installed their own Gentoo buttons at our button machine.
In addition we had a new Gentoo LiveDVD as handout - the "Crispy Belgian Waffle" FOSDEM 2017 edition. For those of you who couldn't make it to Brussels, you can still get it! Download the ISO here and burn it on a DVD or copy it on a USB stick - all done. Many thanks to Fernando Reyes (likewhoa) for all his work!
Finally, for those who are wondering, the "Gentoo Ecosystem" poster from our table can be downloaded as PDF here. It is based on work by Daniel Robbins and mitzip from Funtoo; the source files are available on Github. Of course this poster is continous work in progress, so tell me if you find something missing!

Friday, September 16, 2016

PRL accepted: Secondary electron interference from trigonal warping in clean carbon nanotubes

http://www.akhuettel.de/publications/fabryperot.pdf
We're very happy to announce that a few days ago one of our manuscripts, "Secondary electron interference from trigonal warping in clean carbon nanotubes", was accepted for publication in Physical Review Letters

Imagine a graphene "sheet" of carbon atoms rolled into a tube - and you get a carbon nanotube. Carbon nanotubes come in many variants, which influence strongly their electronic properties. They have different diameter, but also different "chiral angle", describing how the pattern of the carbon atoms twists around the tube axis. In our work, we show how to extract information on the nanotube structure from measurements of its conductance. At low temperature, electrons travel ballistically through a nanotube and are only scattered at its ends. For the quantum-mechanical electron wavefunction, metallic nanotubes act then analogous to an optical Fabry-Perot interferometer, i.e., a cavity with two semitransparent mirrors at either end, where a wave is partially reflected. Interference patterns are obtained by tuning the wavelength of the electrons; the current through the nanotube oscillates as a function of an applied gate voltage. The twisted graphene lattice then causes a distinct slow current modulation, which, as we show, allows a direct estimation of the chiral angle. This is an important step towards solving a highly nontrivial problem, namely identifying the precise
molecular structure of a nanotube from electronic measurements alone.

"Secondary electron interference from trigonal warping in clean carbon nanotubes"
A. Dirnaichner, M. del Valle, K. J. G. Götz, F. J. Schupp, N. Paradiso, M. Grifoni, Ch. Strunk, and A. K. Hüttel
accepted for publication in Physical Review Letters; arXiv:1602.03866 (PDF, supplemental information)