Posts in category Research
Visit Yale
I’m just back from United States. From Monday thru Friday I was in New Haven visiting Yale university. The program included giving two talks, meeting faculty and postdocs of Department of Physics and Department of Applied Physics, collaborating with Leonid Glazman on our longstanding project in adiabatic dymanics of superconducting junctions.
This was a very interesting visit, I will write later about it.
Half-Josephson laser
finally shines in the dark! We (Frans Godschalk, Fabian Hassler and me) have submitted this article to cond-mat, please find it here.
This is first submission of Frans Godschalk: congratulations, Frans!
No chance to devise a polaron,
modern society does not want it, my project about this has been finally rejected. It got an overall mark of 3,0 whlie the threshold this year stand at 2,4. Sad news, yet nothing to be done: competition is tough.
There is however a secret back-door opportunity. My former student Izak Snyman is now a faculty in South Africa. Perhaps they would be interested? We’ll see …
Visit Goteborg
I’m writting in a rather reversed chronological order, since I’ve been to Goteborg (correct English name would be Gothenburg) already more than two weeks ago. Yet it was a wonderful visit organized by Vitaly Shumeiko, and I ought to mention it.
Goteborg houses many nanoscientists, much more than Delft. Formally they are separated into Goteborg University and Chalmers Technical University, yet people from these different organizations sometimes even share offices. Owing to geographical proximity of former Soviet Union and rather harsh climate, an appreciable fraction of nanophysisists speaks Russian. Two of Goteborg faculty are my close university fellows: we graduated in 1982 from the same study-group of 18 people (where – guess now I have to mention it all the time – Andre Geim belonged as well). Know very well the most of Swedish-speaking elder faculty. However, despite many connections to the place, I have not been to Goteborg for 18 years.
Main events took place on Sept. 24. In the morning, I met Yari Kinaret: those were hours of nanomechanics. He introduced a bunch of students – of him, Leonid Gorelik and Robert Shekhter – and who did not have time and had to talk fast. In two hours I’ve heard more new nano- and micromechanical ideas than in two previous years. Leonid Kuzmin, with whom I worked in Moscow University many years ago, shared with me his ideas – some were more like dreams – about superconducting bolometers. He’s also shown interesting preliminary measurements of highly resistive superconducting forks. After lunch I met Per Delsing and Chris Wilson who do quantum optics with microwaves – and do it with zeal and style. They, Tsukuba gang and several other groups are active in microwave artificial atoms. Next was Serge Kubatkin, he was pioneered graphene on SiC substrate and has shown me astonishing Quantum Hall plateaus. Vitaly Shumeiko, fellow theorist, told about his work on Andreev dots under irradiation: a topic Ciprian and me will tackle soon.
To complete the (scientific) joy of the day, I was invited to a warm party and exclusive diner in Leonid Gorelik’s place. Officially we cannot talk about science at the party: yet me and Leonid went out for a smoke and there we discussed a bit of nanomechanics.
Eliashberg 80
One of the reasons to visit Russia was the fact that my supervisor, Gerasim Matveevitch (Sima) Eliashberg has turned 80 years old this year. Landau Institute for Theoretical Physics has organized a three-day conference to honour him and Vsevolod Gantmacher (75), and I was invited. Teun Klapwijk also got there, to commemorate the fact that one of his first experiments was to confirm an effect predicted by Eliashberg. Wonder if Teun could fully enjoy the talks: it appeared unexpectedly that the working language of the conference is Russian…
Prof. Eliashberg is still active and kicking. He attended all the talks. Once upon time, he has provided a great support to BCS theory of superconductivity by extending their approach to more realistic “strong coupling” case. He has also pioneered the use of random matrices in condensed matter physics, among other things. I greatly appreciate him teaching me. The point is that in my diploma thesis-PhD times I was rather unconventional younster. If I had a teacher of lesser patience and readiness to listen to baby-talk, I would never ever become a physicist. Well, by that time I thought that having such a supervisor is quite usual. Since that I met thousands of physisists, quick and deep, bright and active, but till now I haven’t met anybody who was as kind and noble as Eliashberg.
Long live Eliashberg.
Andre Geim
and Kostya Novoselov have won Nobel prize on Oct. 5, 2010. That you undoubtedly know: what can I add to it?
First of all, I share alma mater: Fiztekh, Moscow Physical-Technical University, with the winners. This is an establishment that prendended to be excellent and even exclusive during Cold-War era, and honestly tried to achive this. Despite Nobel-stamped quality of their research, Andre and Kostya are typical fiztekhi, Fiztekh graduates, and their win is our win as well.
By chance, on the same Oct. 5 I came to Fiztekh after 25 years of being away. My goal was to deliver a lecture to younger generation: they are interested in nanoscience. I will perhaps describe the lecture in a separate post. Anyway Andre and Kostya have provided an excellent introducton for this lecture.
And personally I know Andre pretty well always being delighted with his creativity, assertiveness and humour. I hope that the prize won’t be a signal for him to cease his constant quest for novel things, and next to levitating frog, gekko tape and graphene he will come up with new sensational discoveries.
Jens Michelsen
has obtained his PhD degree on September 23 in Goteborg. His promotor was Vitaly Shumeiko, and I was appointed as a faculty opponent.
This means I had to work, and, on Dutch standards, had to do work of six: the dramatic part of the defence has lasted the same hour as in the Netherlands while I was alone to question the candidate. Jens has answered very good all complicated theory questions, and me and the audience were impressed. His thesis addresses dynamics of Andreev states.
Jens has spent 10 years studying in Goteborg and will soon depart to Karsruhe for the postdoc with Gerd Schoen, something that I also did many years ago. Best luck, Jens, I am sure I will hear more of your scientific achievements.
Thomas Picot
has obtained his PhD degreee on September 22 in Delft. Hans Mooij and Kees Harmans were the promotors.
Upon his arrival in Delft, Thomas has impressed me with his strange views on quantum detection. By “strange” I do not imply “incorrect” or “unconventional”, just “strange”. The impression was so strong as to motivate me for a research project on qubit detection. The project is accomplished but still waits for a write-up, already for years.
Meanwhile Thomas has been working on practical quantum detection. His views have become less strange as to judge from the thesis, the achievements have multiplied. The committee members were most impressed by the revival of swithiching detector Thomas made.
During the defence, we’ve discussed his proposition about working on character, and he’s impressed me once again with razor-sharp definions of the subject.
Giant current fluctuations
in an overheated single electron transistor is a study which I’ve done with Matti Laakso and Tero Heikkila from Helsinki. The highlight of the research is that the distribution of the current may become a power-law, that makes it quite distinct from usual distributions.
Power-law distributions are rare in physics. It is third time in my life I encounter one. First time it was yet at university. I’ve read and memorized that the distribution of radiative losses by a fast charged particle in a media has a power-law tail. That formally renders the radiative losses unmeasurable (control question: explain why). With this piece of knowledge, I’ve managed to pass an examination I was totally unprepared for. Was a fun to use the trick once again.
See the article at
http://arxiv.org/abs/1009.3400
Week Konstanz
This is yet another overdue report: week 16-20 August in Konstanz.
Konstanz is a beautiful city at Bodenzee lake and German-Swiss border. My old collaborator Wolfgang Belzig works there. Yet none of those was a reason to visit there this time.
Guido Burkhard and Daniel Loss have had a splendid idea to organize a school/workshop on spin-based quantum information processing. Besides an interesting and “hot” central topic, the gathering was exceptionally well planned: all aspects and directions of the activity were represented by prominent speakers giving long and informative talks, younger people presenting newer things in shorther talks, big number of students with posters, opportunities for discussions etc. Not mentioning exclusive location and good food:)
I talked about spin superconducting qubits.