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Posted in 2015

International Women’s day

for me is immediately associated with soviet time of my youth. My mom likes it very much. She’s with us now, so I brought her flowers in the morning.

Well, I’ve figure out that the day is extensively celebrated in Delft: look here. I read the long program to my mom. No, nothing inspired her. I believe there is a conceptual difference 🙂

Here and now, it’s almost exclusively a day for women about women. In soviet times, that was a day of man’s courtesy: women got gifts and flowers, both required courage and effort to bring. That made it a way more romantic 🙂 Like this: mimosa

Classically Quantum

That was the lecture I gave today in the course Fairy Tales. Usually I give this one in the end of the whole course since I think it demonstrates very neatly the power of theoretical physics. Technically, it is about the correspondence between the classical 1d statistical mechanics and quantum mechanics. We looked at path integrals, transfer matrix methods, and learned that a sushi roll is better be sliced before consuming 🙂

Well, that was forth lecture I gave this week. Kind of a big and pretty tiring fluctuation :(.

Fourth lecture Quantum Transport

was about extra conservation laws in quantum mechanics as compared to classical one, magic mirrors that permit to look through the self-averaging, templates of theories … We have started circuit theory of transmission distribution.

I’m still having half-lecture shift, this is annoying, yet I still do not have an opportunoty to change the situation.

Fifth lecture Advanced Quantum Mechanics

I took time slot of a Thursday problem-solving session. This was mostly to achieve a better synchronization between the lectures and PPS. Unfortunate effect on this is that the students are bored with my face since I show up too often. So I was told by my colleagues. I have to believe in this since I myself is seldom bored with my own face.

Anyway, this was my favorite topic(s): superconductivity and superfluidity. I enjoyed talking and told at least three “side” stories, in particular, the legend about Leiden street boy. I think I could do all important things on time.

There was a question about some skipped algebra in the break. I always get confused with such questions and perhaps did not react adequately. Actually, for all twenty years I’m giving the lectures I never managed to derive for myself a golden rule that would automatically tell me how much derivations I need to hide. So I always remain in a stressfull balance between “…substitute zis to zis and see how beautiful is the cancellation of factors of 2 in the numerator and denominator…” and “as, you know, you can easily see …” Between Scylla and Charybdis is my endless way 🙂

Fourth lecture Advanced Quantum Mechanics

We got through the formal part of the course – and started enjoying the examples! Magnetism, the puzzle of centuries:) I’ve put quite some new material I’ve never taught before. This was about magnons and other excitations in a magnet. I was not sure I could do it in time from the first attempt and warned the students in the beginning that perhaps I will have to skip this part.

Well, it went better than expected, though I had to skip a couple of slides. Moreover, it looks I could catch an attention provoking questions. The idea of the energy splitting of two spin subbands has spontaneously originated in the audience, a way before I was planning to talk about it. Nice 🙂

Anyway, there is room for improvement for the next time.

Third lecture Quantum Transport

was half-inteference, half-restoration of Ohm’s law – I still keep half-lecture shift. The advantage of this was that I could repeat the double junction that plays a key role in both topics. It occurred to me that the audience was more active than in former years at the interference part – good, but less active for Ohm’s law. Was I too monotonic for the second half of the lecture or the student’s tastes fluctuate from year to year?

Exact correspondence

Me and Mohammad Ansari have submitted a paper that concludes a nice piece of research on Renyi entropies. We have found an exact relation, like fluctuation-dissipation theorem, that relates physical and unphysical quantities: you can guess the implications:))))

Here is the link

Exact correspondence between Renyi entropy flows and physical flows
Mohammad H. Ansari, Yuli V. Nazarov

We present a universal relation between the flow of a Renyi entropy and the full counting statistics of energy transfers. We prove the exact relation for a flow to a system in thermal equilibrium that is weakly coupled to an arbitrary time-dependent and non-equilibrium system. The exact correspondence, given by this relation, provides a simple protocol to quantify the flows of Shannon and Renyi entropies from the measurements of energy transfer statistics.

Problem-solving session AQM

Neither Michael nor Albert could help me on this day: I had to do PSS myself. Fortunately all students were in place with the presentations and spoke sense. I also gave some practical advices on second-quantization calculations: hope it works. Besides, I asked students to fill in a survey about the course. I will investigate the data collected and present the results on next week.

Isaiah 2:4

read this on Wednesday in attempts of improving my spiritual life 🙂

And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruning hooks: nation shall not lift up sword against nation, neither shall they learn war any more.

Well, this hardly worked. Instead of enlightening, I felt irritation and anger. Say, 20 years ago this citation seemed to be not far from the realization. Nowadays Evil rises head again: it does so in most stupid, shameless and hypocritical fashion. Who is sillier: people raging for arms or me with my optimistic beliefs?

Third lecture Advanced Quantum Mechanics

was the core of the course: second quantization. It was pretty formal, though I did my best to outline the logics and motivation behind the formulas. The students were warned that it will be boring, so they remain rather accepting. I went slower trying to establish better contact. This resulted in a time problem: in fact, I said only few most important things about fermion quantization. Luckily, it is almost the same as for bosons.

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