Posts in category Research
Unphysics of quantum information
rocks. I’ve just finished my major contibution to the field: paper on flows of Renyi entropies.Will put in on cond/mat in several days.
FQMT11
that is “Frontiers of Quantum and Mesoscopic Thermodynamics” was a relatively large conference in Prague where diverse aspects of quantum mechanics have been discussed. It has been organized (mainly) by Theo Nieuwenhuizen and Václav Špička. It’s been long I was at such broad yet interesting conference that covered everything from black holes to biomotors and I enjoyed much. Ciprian and Frans were also there. Many talks (hopefully, including mine) were inspiring and I was able to get new ideas and finish some hard calculations.
The plot of the organizers was to habituate us to everyday portion of classical music so that we get use to it, develop an addiction and will attend further conferencies in series. This has worked quite well, I must admit. Being a Slav, I could appreciate typical Slavonic hospitality that stems from the deep of the heart, may look clusmy and eccentric, yet leads to unusual and memorable experience. To give an example, we have been welcomed by His Eminence Dominique Duka, Archbishop of Prague, in his seat cathedral and were allowed to get intoxicated in Senat of Check Republic.
Many thanks, Theo and Václav, we look forward to the next conference like this.
Renyi Entropy Flows
capture my mind these days. I was busy with this research last summer, yet I still have to pack it and write down an article. There were several little things remaining to do: upon close inspection, they appear very interesting and require time investment. Next Wednesday I’ll give a talk in Prague about it.
Half-Josephson Laser
has finally been accepted for publication in Physical Review Letters: congratulations to Frans! The consideration took eight months.
Hans Schumacher
from Physikalisch-Technische Bundesanstalt Braunschweig, German metrology center, gave a talk today. The main direction of his research is to make a practical electric-current standard that uses electron counting in Coulomb blockade regime. Many teams, including that in Delft, have attempted this 20-15 years ago but have to stop. Hans Schumacher boldly took the road that has considered to be a dead end and has demonstrated to us a significant progress as well as a hope for even further progress. I like his strive very much and wish him best sucsess.
That was positive and encouraging part of the talk. There was also a negative and dissapoinig part. It appears that the physical factor that stopped the research 15 years ago – undesired co-tunneling processes – has been completely forgotten today. At least the speaker could not give correct esimations of the precision limitations owing to this factor, and I suspect that people helping him did not think about it too. Find this outrageous since the factor has been discussed in the literature in quite some detail and presents common knowledge in quantum transport. I suggest that the authors, invoved editors and especially anonymous referees of
Phys. Rev. Lett. 104, 186805 (2010)should immediately attend my master course in quantum transport. This seems the only way to restore the continuity of scientific progress:)
Topological excitations
will become a part of the book on Advanced Quantum Mechanics I write with Jeroen Danon. I’m currently squeezing the material to a chapter devoted to superfluidity. It’s a difficult piece of writting: yet I dream it will be a good one.
The trick to implement the concept is to consider the superfluid in lower dimensions where vortices have finite energy and can be regarded as elementary excitations. I also hope to be able to say something about Feynmann’s roton variational function: a gem almost forgotten in modern education.
Few skeletons in every genome
Today we have had another Kavli Colloquium. Actually, my day was busy and nervous, and I thought I could skip “this bio stuff” and concentrate at work at hand. I’ve changed the decision at the last moment and have not regretted: in fact, I think it was one of the best colloquia I ever attended.
Though there was hardly any physics. Stephen Quake, prof Bioingenering from Stanford and enterpreneur, has neatly and skilfully tuned the presentation to the perception and level of general physical audience, I appreciate much his effort to get us following. The talk did not sound any “biological” though it was.
It was about reading genomes of individual humans by means of single-molecule DNA sequencing. Stephen Quake is a leading palyer in the field. Three years ago he read his own genome for $ 50,000 cost. According to his projections, this cost can drop to $ 500 whithin years. The reading of someone’s genome can become as usual as a blood test. And perhaps will become compulsory as a drug test (in order to descrease costs of medical aid by early detection of potential gene-related medical problems). The positive sides of it are clear (though, as was stressed in the talk, less obvious than we’d like them to be). With a bit of imagination, one can picture negative sides of it (don’t want to do this here, leave it as an exercise for the reader).
When I was a kid, I read stories about scientists whose work reshapes the world within years. I think today I finally came reasonably close to seeing one. Stephen Quake looks very human, more human than most profs of science (me including). That’s why I sympathize with him and wish him to never regret the opportunities his research may unleash…
No Coulomb Blockade of Majorana Fermions
you, dear reader, and all modern society will have to live without spectacular achievements in this research direction.
My research proposal described in this post has been rejected in the course of our national competition, FOM Projectruimte. In comparison with the last year competition I invested more time to the writting, have brought more original and more experimentally relevant ideas, have discussed proposal with many and incorporated their feedback.
The result of these actions was evident and imminent: the proposal has been rejected faster and with worse mark. A modern referee does not have time to read the proposal, and expects to see the things expected. Any unexpected creativity is punished immediately, at the level of instinct.
Yet the creativity was certainly present in the marks I get. The referees suppose to give three marks: “scientific quality”, “risky character”, “total assesment” that supposed to summarize the two. Only the third one counts, while the first two are given for fun. In that case, the fun was all mine: 3.0 “scientific quality”, 3.2 “risky character”, 3.5 “total assesment”. Surprised, I asked the FOM functioneers for a comment. Got nothing except “such things happen”. They happen indeed!
Julia Meyer
has been visiting tuesday-wednesday this week. She’s a faculty in Grenoble now, after being in Germany and a loong time in US. I like very much her serious, thorough and ingenious approach to theoretical physics: something rarely seen in her generation/our field.
She gave a talk about various aspects of 1d interacting electrons. I especially liked the last part devoted to ordering of classical electrons in 1d confining potential. It’s a beautiful and context-rich problem that I also touched many years ago.
Conference in Mallorca,
that’s where I’ve been sunday-thusday this week. Rosa Lopez and David Sanchez, faculties of University of Balearic islands, were so kind as to organize it, “Nonlinear spin and charge transport through nanoscopic systems” was the name, many thanks for this. Funniest thing is that we all actually work from 8 till 17, while the weather was nice almost all the time.
Things I liked included:
- the direction of the conference: it beared non-linear stochastic dynamics flavour, the taste that becomes stronger and stronger in quantum transort research
- talks, especially related to electron counting/pumping
- food, and very much
- swimming at a public beach in 1km from the hotel
- a spectacular night thunderstorm in Hollywood style
Things I liked less were:
- the conference mascot was a little red horny devil
- the fact the island seems totally covered by the city
- waking up at 2 a.m to catch the flight there
- going to bed at 4 a.m. after the flight there