Finite square well. Setting up the problem

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  • Опубліковано 28 січ 2025

КОМЕНТАРІ • 37

  • @10seabird
    @10seabird 3 роки тому +9

    Fantastic lectures. I had studied QM before but this presentation makes it so comprehensible

  • @girishtripathy3354
    @girishtripathy3354 4 роки тому +27

    My left ear understood better than my right ear. Thanks prof

  • @igrib5852
    @igrib5852 Рік тому +4

    "You'd better do something about that cough"

  • @GuruCharanGupta
    @GuruCharanGupta 7 років тому +10

    Hi! around @7:48 the subtitle says "and real exponential solutions depend on the sines" 'sines' should be 'signs'
    @15:21 it says "know the sine" but sine -> sign
    @22:29 it says "8x psi plane" it should be "eta-xi plane"

    • @mitocw
      @mitocw  7 років тому +13

      Thanks for the feedback! The subtitles have been updated. :)

  • @jerrydong8224
    @jerrydong8224 3 роки тому +1

    Was searching up the finite curve song and stumbled upon this

  • @silvadexter3222
    @silvadexter3222 7 років тому +4

    very clear !!!! ty for lecturing

  • @aartikhemnani3245
    @aartikhemnani3245 5 років тому +2

    at 19:51 the kappa square + k square = some quantity , But left hand side is unit less but right hand side have some units how it is possible

    • @BL1zZ4Rth
      @BL1zZ4Rth 5 років тому +3

      They are all unit-free.
      [ V0 ] = [ E ] = [ M L^2 T^-2 ]
      [ hbar ] = [ E T ] = [ M L^2 T^-1 ]
      [ m ] = [ M ]
      [ a ] = [ L ]
      k^2 = (2m) (hbar^-2) (V0 - |E|) => [ k^2 ] = [ (M) (E^-2 T^-2) (E)] = [ (M) (E^-1) T^-2 ] = [ M (M^-1 L^-2 T^2) T^-2 ] = [ L^-2 ] =>
      => [ η ] = [ ka ] = [ (L^-2)^(1/2) L ] = [ 1 ] thus unitless ,same with η^2 and we get the same result for κ (kappa) and by extension ξ and ξ^2, since the only difference between k and κ(kappa) is the replacement of the term (V0 - |E|) with |E| which we already know have the same units.
      Now using that [ k^2 ] = [ L^-2 ] ,from the end of my first line of calculation we get:
      z0^2 = (2m hbar^-2 V0) (a^2) => [ z0^2 ] = [ k^2 a^2 ] = [ L^-2 L^2 ] = [ 1 ] and thus is also unitless.

  • @loveforkitten2721
    @loveforkitten2721 6 років тому +3

    You are really wonderful Sir. 😊😊😊😊😊😊😊😊😊😊

  • @ismahanemansouri9268
    @ismahanemansouri9268 7 місяців тому

    Awesome thanks prof 😅 I am watching from Algeria I am a theoretical physicist and qm is crucial for us , or for all modern physics in general 😅

  • @Leonugent2012
    @Leonugent2012 4 роки тому +2

    If you’re able to learn quantum mechanics you can learn it here

  • @shannonramirezslater4909
    @shannonramirezslater4909 3 роки тому +11

    great lecture. Whoever that was coughing like a person on their deathbed, take some cough drops man. That was so distracting

    • @TonalWorks
      @TonalWorks 3 роки тому +6

      Or even better would be to stay at home, and so preventing the whole lecture hall from getting infected. Annoying and also inconsiderate

    • @diags_1109
      @diags_1109 3 роки тому +1

      @@TonalWorks you think that was annoying there is someone in my one lecture that constantly snorts his snot, like the snoring noise, during the first test they were going at it every like 20 or maybe less seconds for an hour and twenty minutes

  • @mwangushyafrancis8383
    @mwangushyafrancis8383 6 років тому

    i greatly appreciate the presentation. i like it

  • @aartikhemnani3245
    @aartikhemnani3245 5 років тому

    ok i think some mistakes are there we can t ignore the negative signs because wave function changes ..

  • @cafe-tomate
    @cafe-tomate 2 роки тому

    Waw that was a blast!

  • @amirkhedri4562
    @amirkhedri4562 Рік тому

    I have a question sir. In the case where |x|

  • @javierortiz2128
    @javierortiz2128 3 роки тому +3

    My professor did her post-doc at MIT and she cannot teach quantum mechanics at all. I had to go to the source to find a better instructor xD

  • @not_amanullah
    @not_amanullah 5 місяців тому

    Thanks 🤍❤️

  • @keshavmittal1077
    @keshavmittal1077 3 роки тому

    sir, what is the meaning of energy is negative?

  • @srivishnudasu1694
    @srivishnudasu1694 5 років тому

    14:06 if we are trying to find energy eigenstates , then they are supposed to be orthonormal anyways. why try to normalize at all?

  • @not_amanullah
    @not_amanullah 5 місяців тому

    This is helpful ❤️🤍

  • @aimalkhan3229
    @aimalkhan3229 5 років тому

    Sir what is the difference between particle in potential well and particle in a box?

    • @res0nanc320
      @res0nanc320 5 років тому +1

      The 'box' is a specific potential well.

    • @vishnuakundi4766
      @vishnuakundi4766 4 роки тому +1

      The box is 3-dimensional and so you will have partial derivates wrt the 3 coordinates of position (instead of just d/dx)

  • @zphuo
    @zphuo 7 років тому

    Why k and kappa need unit-free??

  • @lukschs1
    @lukschs1 6 місяців тому

    Como el picoo, no se entiende nada

  • @peterpalumbo3644
    @peterpalumbo3644 5 років тому +3

    Can you do something about the noise from the audience. It is very hard to listen to the instructor with all the background noise.

  • @adosar7261
    @adosar7261 5 років тому

    Does any force exist in this potential well ? Both inside and outside the well the derivative of potential energy with respect to position is 0 therefore zero force. So what is the point to have 2 different potentials ?

  • @STKeTcH
    @STKeTcH 2 роки тому

    I'm so glad I didn't go to MIT

  • @pankajchaurasia4022
    @pankajchaurasia4022 5 років тому +3

    not good ,could have been more understandable

    • @HumbertLaxness
      @HumbertLaxness Рік тому

      why is it always the Indian complaining, i have seen your quality of lectures on UA-cam lol, completely incomprehensible