Theory of quantum noise and decoherence, Lecture 1

The course will be "not without mathematical rigour", however, the main emphasis will be on physical examples.

[mythic]

Watching this dude clean those chalk boards is easing my soul

[Fransamsterdam]

9:50 The exciting moment in history when it was invented to repeat questions from the audience. Thumbs up!

[rc]

This lecture is so “good” that I can not properly describe its “goodness”. Understanding what can and cannot be attributed to an observable is required by empiricist scientists BUT OFTEN OVERLOOKED by theoretical scientists in the construction of theoretical explanation of experimental results. A proper understanding of decoherence is (imho) fundamental in this endeavor.

[rajathradhakrishnan]

I'm an undergraduate student interested in Open Quantum Systems. First of all, thank you for these wonderful lectures. I had gone through some lecture notes on density matrix and composite systems. Though, I'm able to follow these lectures it would be a great help if you could suggest some online resources to gain more physical insight through solving problems and going through more examples. There are no local edition for the textbooks that you have mentioned and the international edition is really costly. So, it is important for me to have some online resource to back up these lectures.

[alipedram]

Awesome lecture! Can you please zoom into the blackboards a little more for the next lectures? Internet connection speed is very slow in 3rd world countries and YouTube is blocked in Iran. So it is very difficult to watch YouTube videos in HD over here. Thank you very much.

[shodasaksharividya]

Greetings Professor, is there any lecture notes which covers the "Hannover rules" of QM from the very basics? Thanks in advance.

[garywpearson]

I do have a technical question as well -- how does the "no clone" requirement jive with optical Amplified Stimulate Emission (ASE) in which a photon's direction, wavelength, polarization and phase are all "copied" to another photon? A real world example would be the use of Optical Amplifiers in a fiber optics system. This would seem to be a "clone" of the original photon, within of course some jitter.

[garywpearson]

wonderful! Thanx for posting this. :-) Your lectures includes a precise style rarely seen in university teaching, by which I mean your blackboard notes could well become a textbook. Along those lines, are your class notes also available online for those watching your excellent lectures remotely?

[marcuspereira]

Hello Dr. Osborne,
Thank you for this wonderful series of lectures. I have just started watching these and I enjoy your teaching style and methodology. I had a silly question about the hint to the exercise at the very end of the video - you have [ 0.5*( I + \bar{r} .\bar{\sigma} ) ]^2 = 0.5*( I + \bar{r} .\bar{\sigma} ). I understand what I and \bar{r} are. But what is \bar{sigma}? Also how does this relate to the parameterization of \rho that you introduce few minutes before this in the qubit example?
Thank you,
Marcus

[jimmyb]

At 56:50, what's the purpose of the second index α, outside the set designator {} ? Surely, there is just one set of all E_α's ? Perhaps you meant to index with the observable A ?

[adwaitnaravane]

Hello professor, do you have lecture notes for these set of video lectures?

[rafaelbendavid]

Professor, you keep saying that QM is a "probabilistic theory" and thats fine but in your Symplectic geometry course you show that a wave function can be thought of as a Hamiltonian flow on a Kaehler manifold. So what gives :)

[sandeepjoy]

Which book are you following for this first lecture ?

[nesaralititumir]

This formulation seems so different from the usual textbook formulation that we usually study in books like Sakurai or Landau. Is there any instance where the consequences of this formulation differ from consequences of the usual formulation?

[iiserguy]

Sir, I can not see clearly what book's name you have written on the board. Can you please rewrite them in the comment section and pin them. It's a request

[junfan]

Can the condition that the density matrix is hermitian be from the other two conditions?

[kirkmcgraw]

I wish I didn’t think this shit was for nerds when I was a kid.. Maybe someone can observe me not being a dummy 30 yrs ago and change my super “disposition “ 😞 🤷🏻‍♂️