Posted in 2015
Second lecture Quantum Transport
was on Friday. I was supposed to start with the interference. However, there was a sweet topic of counting statistics left from the first lecture. Since I liked the topic, and since one needs to brush some probability analysis to understand the issue, it went slower than expected. So I’ve managed to do only a half of the interference lecture. Well, this is rather inconvenient – to have a half-lecture shift, but I do not want at the moment to make the shift integer 🙂
Charles Markus
from Copenhagen, a brilliant experimentalist who has now mostly concentrated on Majoranization of semiconducting nanowires by connecting those to superconductors – has given a talk on Thursday.
He started with reporting successes in nanowire growth: nanowires can be better contacted with superconductors, and can be made in t and h shapes. He has shown “hard gap” – looked good, finally in place after years of technological search.
Then we got the report on experimental results – some fresh, right from the oven. The results in “Delft geometry” seemed clean but I did not quite see the gap as hard as promised. The results in “Copenhagen geometry” were a superconducting island has been attached to the nanowire seemed more fun – I will have to revise those carefully.
Wilfred van der Wiel
from Twente University gave a Nanoscience seminar on Wednesday. I vividly remember him as an outstanding PhD student, have not seen him for years and was delighted to see no significant change: in the position of full professor, he reminds sharp, handsome, nice and does outstanding research.
There were two topics. First one: Wilfred has investigated the conductance (well, if you can call inverse GigaOhm a conductance) of molecular wires thread in zeolyte crystal. The conductance could be changed by order of magnitude by tiny magnetic field in millitesla range. The mechanism of the effect must be related to nuclear spins and as such is the same as for the spin-blockade lifting in double quantum dots. The details remain unclear for me: yet the effect is there and is a record-strong.
The second topic has fascinated me even more. The physics was rather simple: Coulomb blockade in a pile of gold nanoparticles carelessly collected between a multitude of electrodes. A neat physical realization of complete and hopelessly incomprehensible mess. Yet it appears that that it is the mess that motivated the researcher. Wilfred managed to demonstrate that with the proper tuning (based on genetic algorithm) the pile can work as any of the logical gates! I reckon this work will have a big philosophical impact (seriously). It proves that electronic components can be made from anything (substitute “anything” with a stronger word if you like).
Facultymeeting
English at our University is very flexible reflecting a variety of meanings with very simple constructions. If you say: faculty meeting – this would be most likely the gathering of faculty of a small department, such as mine. If you say: facultymeeting – you imply an act of interaction of our Rector Magnificus Karel Luyben with a handful of people representing all faculties, levels and occupations at our huge technical university.
I have attended one on Tuesday. The previous session I was present for was three years ago. I must say I did not like that one: the people talk stiffly and officially, hardly interacted and listened to each other. This session was much better: the organization has drastically improved, the atmosphere was open and friendly, people spoke themselves out and this was helpful in many respects. Perhaps last part where we were forced to play a manager-course-like game was less inspiring for me, but the total was much better than I expected.
Among other topics, we have discussed a new political development: it looks like soon the Associated Profs will be able to promote their PhD students (it is a peculiarity of Dutch law that they cannot do it officially, and this is usually experienced as a psychological tension by many generations of Associated and Assistance profs). Great news! – yet my concern was that this may invoke more control than it is needed in intimate relation between a student and its supervisor. It appears, however, that the rector has other concerns, of more organizational nature.
We have discussed how to improve the quality of teaching: please do not smile, the discussion was rather substantive. I was surprised that many colleagues support the idea of promoting people to full profs mostly for their educational merits – at the moment, the research is main criterion. I’ve double opinion on this. From one hand, I see some people who have concentrated on education, work hard and excellent – and remain underpaid and un-promoted. From the other hand, long time ago in Russia and more recently in France I saw education-concentrated profs – frankly, I’d rather not. There must be a flexible solution to the problem.
Mutli-terminal Josephson junctions as topological materials
This is the title of the manuscript I have submitted on Tuesday with my Grenoble friends Julia Meyer, Roman Riwar and Manuel Houzet. Mmm, perhaps I exaggerate in excitation, but this looks the most significant piece of research I accomplished for last years. The preprint is not available yet, but I expect this to happen soon 🙂
Second Lecture Advanced Quantum Mechanics
on this Monday was reasonably well attended. The topic: identical particles, despite importance and fundamental interest, was rather easy, both for me and for students. This gave enough time to go slow and even made an actual experiment with identical particles 😉 There was a good contact. Hope we can go on in this pace.
First lecture Fairy Tales
was about KdV equation, the spectacular advance of early Dutch science. There were many students. I was flattened with the fact that most were familiar with the Lagrangian, and variational calculations in this context. I begin to believe in progress and knowledge accumulation since I did not quite see this in former generation.
Moreover, the students were able to correctly describe the activities of a theoretical physicist. Well, I was rather inspired with this fact and has spent too much time on introduction for the sake of exact solution technology – just had time to mention it briefly.
First lecture Quantum Transport
has happened today. I was pleased with the number of students: it is significantly higher than year ago. Yet in comparison with the former generation the students looked kind of shy being not eager to respond on my questions and provocations. Perhaps early morning is to blame. Nevertheless, I reacted by going slower. We did not even touch counting statistics: left for the future).
Problem-solving session Advanced Quantum Mechanics
took place on Thursday. Since it was not my show – it is that of Michael Wimmer and Albert Gonzalez – I attended only the first part. I was extremely pleased with the student presentation. Basically, it was about the topic that I have to skip during the lecture and felt guilty about since the topic is nice and rather important for the whole course. The presentation was next to ideal: the topic has been presented clearly, the audience was attending, the message got through.
There were many students at the session. Actually, we have run out of the presentation topics: more students want to present, we need to arrange some extra sessions for this in the second half of the semester.
Christian Glattli
from Saclay has visited us on Wednesday this week. We have had an opportunity to chat about his research on graphene plasmonics and his plans to utilize edge channels in graphene, as well as about my plans with chiral electrons.
His talk was about “levitons”, his recent research on noise in quantum point contact. This drew me very philosophical: I began to think about most general definition of a particle and even ask Christian about)).