L2.2 Anharmonic Oscillator via a quartic perturbation

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  • เผยแพร่เมื่อ 16 ก.ค. 2024
  • MIT 8.06 Quantum Physics III, Spring 2018
    Instructor: Barton Zwiebach
    View the complete course: ocw.mit.edu/8-06S18
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    L2.2 Anharmonic Oscillator via a quartic perturbation
    License: Creative Commons BY-NC-SA
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ความคิดเห็น • 35

  • @helloby4125
    @helloby4125 4 หลายเดือนก่อน +1

    Watching this after Watching bender's lectures gives you the feeling of standing on the shoulders of giants

  • @cristivoinea8742
    @cristivoinea8742 4 ปีที่แล้ว +23

    If you watch his lectures on 1.5x they're actually pretty good

    • @lakhan7179
      @lakhan7179 3 ปีที่แล้ว +2

      👌👍

    • @meghamanihaldar648
      @meghamanihaldar648 3 ปีที่แล้ว +2

      Hey.... i do this🤭🤭... sir is awesome

    • @meetghelani5222
      @meetghelani5222 5 หลายเดือนก่อน

      Oh yes, doing the same.

  • @meghamanihaldar648
    @meghamanihaldar648 3 ปีที่แล้ว +11

    Sir it's my humble request to make videos on the course of relativistic quantum mechanics..... your lecture is awesome sir..just awesome .....its my request to mit.... it'll help a lot

  • @cngrinder9423
    @cngrinder9423 3 ปีที่แล้ว +3

    Can someone please explain me why he gets these results when doing bra(0) (a+a dagger)^4 ket(k) or ket(0)? I don't understand it

    • @MrFuncti0n
      @MrFuncti0n 3 ปีที่แล้ว +2

      for bra(0)(a+a dagger)^4 ket(0), expand out (a+a dagger)^4, noting that a and a dagger do not commute. Then, apply this expansion to the state ket(0) -- you will find only the contributions a*adagger*a*a dagger and a^2*a dagger^2 put between bra(0) and ket(0) will give a nonzero result, as the other terms will either annihilate the ground state or be orthogonal (e.g., bra(0)ket(2) = 0). Similar considerations apply to other matrix elements.

  • @prabhatp654
    @prabhatp654 2 ปีที่แล้ว +1

    Why this argument of asymptomatic expansion is justifiable? If it's an infinite sum, it says that for any value of lambda, your ground state energy will be infinite? Doesn't it mean that the assumptions (of series expansion) you took, in the beginning, are false?
    What is happening?

  • @JohnVKaravitis
    @JohnVKaravitis 4 ปีที่แล้ว

    1:30 Then the dotted line s/b inside the parabola.
    17:20 Please close your parenthesis.

  • @bonnome2
    @bonnome2 5 ปีที่แล้ว

    Could you please make an better title? It can be really unclear from the title what the previous lecture is.

  • @cikif
    @cikif 5 ปีที่แล้ว +2

    13:41 he says "the bra"

    • @bonnome2
      @bonnome2 5 ปีที่แล้ว +1

      What is your point? He is talking about the bra + operators he underlined on the previous board.

    • @cikif
      @cikif 5 ปีที่แล้ว +2

      so that whoever is in charge of adding subtitles can fix it

    • @c8adec
      @c8adec 5 ปีที่แล้ว +6

      He actually says "the bruh", a physics term

    • @Skumar-rg4hd
      @Skumar-rg4hd 3 ปีที่แล้ว

      Yes it is clearly "bra" came from bracket

    • @DragonWarrior1524
      @DragonWarrior1524 3 ปีที่แล้ว

      No it's Cali dialect for "the brah", like his homies

  • @ankykolo6526
    @ankykolo6526 5 ปีที่แล้ว +2

    The worst lecture I have ever seen. Congratulations MIT !.
    This guy isn't even teaching, he is just talking to himself. LOOOOL

    • @bonnome2
      @bonnome2 5 ปีที่แล้ว +4

      Some forms of lecturing are better for some than others. Most people find him pretty good.

    • @danielgeorge7466
      @danielgeorge7466 5 ปีที่แล้ว +13

      You're kidding, right?

    • @lobisw
      @lobisw 5 ปีที่แล้ว +3

      I learnt plenty from this, so it can't be that bad. Plus I've been to some shocking lectures. So it must at least be decent.

    • @isaacwesterback9127
      @isaacwesterback9127 4 ปีที่แล้ว +1

      ahh yess he should def be having an open class discussion for QM with undergrads im sure they would learn wayyy more lmao /s

    • @dsanjoy
      @dsanjoy 4 ปีที่แล้ว +10

      It's lecture 2.2 of QM-III and he is trying to demonstrate how to use the perturbation technique to approximately solve an unsolvable problem. What did you expect? Some pop-science s**t ?