Bound states, scattering states, and tunneling

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  • Опубліковано 4 гру 2024

КОМЕНТАРІ • 45

  • @deeponjitbose8188
    @deeponjitbose8188 4 роки тому +11

    Excellent Explantion! Such explanations were not explained with such mind blowing graphical stuffs in any of the popular books I read. A Must watch for every Quantum Physics Students.

  • @NihhaarRC
    @NihhaarRC 9 років тому +10

    The best lecture in quantum mechanics...

    • @marrytesfu3163
      @marrytesfu3163 5 років тому +4

      three years later and still the best

    • @woofle4830
      @woofle4830 4 роки тому +2

      four years later and still the best

    • @daltonmooring2573
      @daltonmooring2573 4 роки тому +1

      five years later and still the best

    • @rimon9697
      @rimon9697 3 роки тому +1

      8 years later and still the best

    • @ijjijoiuj9j558
      @ijjijoiuj9j558 Рік тому +1

      9 years later and still the best

  • @Dua99999Ve
    @Dua99999Ve 11 років тому +8

    Thank you for all of your videos

  • @κπυα
    @κπυα 2 роки тому +2

    *Bound* *State* Trapped particle.
    *Scattering* *State* If E > V(x) when x→+∞ or x→ -∞.
    E₁ (Bound State)
    E₂ (Scattering State)
    E₃ (Scattering State)

  • @andres.manurung2551
    @andres.manurung2551 4 роки тому +1

    Thanks for your explanation, really hope you well

  • @swizzbeats1212
    @swizzbeats1212 8 років тому +3

    You're so good!

  • @YourAverageHater
    @YourAverageHater 9 років тому +3

    E1: bound state
    E2: scattering state since E>V(-inf)
    E3: free particle/scattering??

    • @UmmUkashah
      @UmmUkashah 6 років тому +1

      how can you deduce that?? I coudnt understand the scattering state at all :(

    • @sayanmondal4570
      @sayanmondal4570 6 років тому +4

      The state is scattering if E>V(-inf)..... Scattering state basically tells us that the wavefunction extends upto infinity and is not non normalizable... hence we require Fourier transform and other trcks to superpose the wavefunctions and get a sensible wavefunction describing a particle

    • @manishsingh-vk8if
      @manishsingh-vk8if 5 років тому

      How can E3 be scattering state ? It looks all free.

    • @narek323
      @narek323 3 роки тому +2

      @@sayanmondal4570 Not really, you don't require Fourier transforms just because it's a scattering state. The Fourier transform is also useful for the particle in a box, which is a bound state.

  • @shibaneethakur5035
    @shibaneethakur5035 3 роки тому

    Bound state is confined with in one region,how can we take the equations in other region for E

  • @pendalink
    @pendalink 6 років тому +1

    Thank you sir

  • @jimdogma1537
    @jimdogma1537 10 років тому +1

    That's really interesting. So does that mean that properties of the universe outside a potential well do NOT display quantum effects? Does this also mean that angular momentum is not quantized at energies well above the potential, etc.? Also, what about quantization of the the EM and gravity field way out in intergalactic space? If there's ostensibly no EM or gravitational potential fields out there, does any quantum behavior exist? I thought that the loop quantum gravity guys, etc,, were trying to build their model on quantizing the gravitational field.

    • @sphericalchicken
      @sphericalchicken  10 років тому +10

      The properties of the universe outside a potential well still display quantum effects -- the scattering states are still described by wavefunctions, after all, so they still exhibit uncertainty, wave/particle duality, etc. By "quantum effects", people generally mean more than just quantization of the energy levels. As for angular momentum, I can't say much here since this video was only talking about a 1-d quantum system and you can't have angular momentum in one dimension, but suffice it to say that angular momentum (for example of two masses stuck together by a rod) is quantized even if the object is floating off in the blackness of space.
      As for quantization of the EM and gravitational fields in intergalactic space, you're rapidly getting out of my area of expertise, so you'll have to continue to a treatment of relativistic quantum mechanics and/or quantum field theory to get a good answer for how the electromagnetic field is quantized. The short answer is that while there won't be a "potential" as described in this video and thus the energy of a single particle might not be quantized, the energy of the overall electromagnetic field comes from an ensemble of particles, and the number of particles has to be an integer, so you still have a quantized system, counting particles at a variety of energies instead of counting energy levels of a single particle.

  • @Dekoherence-ii8pw
    @Dekoherence-ii8pw Рік тому

    3:25 Kittenic energy? I prefer the Pupperic energy, myself 🙂 (But only if it's a Smol amount of Pupperic energy).

  • @sayanjitb
    @sayanjitb 4 роки тому

    Dear sir, at the time 15:32, what is the difference between QHO bound state and the given second example on scattering state? I found both of them identical though! Can you please help me out? TIA

  • @nusratriaz310
    @nusratriaz310 3 роки тому

    Great sir

  • @frede1905
    @frede1905 4 роки тому

    This was a cool video, but I just have a question: what if we have a bound state (so E

    • @shankhadipbhattacharjee528
      @shankhadipbhattacharjee528 2 роки тому

      when the wave function blows up/down it is no more in the Hilbert space as the function won't be square integrable. right ?

  • @timetraveller1237
    @timetraveller1237 8 років тому +1

    this is a great lecture but i have one question in the lecture on infinite square well you said the wavefunction must be zero at the boundary conditions but in this lecture you say the wavefunction gradually approaches the zero value only after the boundary conditions. i am very confused? please help!!!!

    • @brno322
      @brno322 8 років тому +6

      It must be zero at the boundary because it's an infinite square well, i.e., the particle would have to have an infinite amount of energy to get through the infinite potential. In this case, it is a finite well, and the particle can get through the barrier with a finite amount of energy, even if it is less than the potential, which is due to tunneling.

    • @timetraveller1237
      @timetraveller1237 8 років тому +1

      thanks that helped

  • @learngermanwithvanessa
    @learngermanwithvanessa 2 роки тому

    I'd say:
    E1 bound
    E2 scattering
    E3 scattering

  • @istainblack
    @istainblack 7 років тому +1

    In most of these graphs (such as the ones describing the quantum behavior), would it have not been more accurate to call the y-axis E for total energy instead of V(x)? I am prabably just misunderstanding...

  • @Skitzy.ok.
    @Skitzy.ok. Рік тому

    Found this channel from a rhcp guitar cover, interesting

  • @abhinandanmehra7765
    @abhinandanmehra7765 3 роки тому

    If you profesor or anyone watches my comment then kindly spare 1 minute or a half in answering that. I am following your Lectures religiously I got 2 questions for you professor 1. Are your videos uploaded in sequential manner. ? 2). Which textbook you would recommend as a freshman to quantum mechanics? I will be extremely grateful towards you

    • @hershyfishman2929
      @hershyfishman2929 3 роки тому +1

      These lectures follow Griffiths QM, and they are ordered sequentially according to that book.

    • @abhinandanmehra7765
      @abhinandanmehra7765 3 роки тому

      @@hershyfishman2929 but he haven't thought parity operator time dependent perturbation theory wkb principal

    • @hershyfishman2929
      @hershyfishman2929 3 роки тому

      @@abhinandanmehra7765 indeed those are not in Griffiths book up until here

  • @manuelsojan9093
    @manuelsojan9093 6 років тому

    is V(x) potential or potential energy? this is so confusing

  • @MiguelGarcia-zx1qj
    @MiguelGarcia-zx1qj 3 роки тому

    I think that the explanation of "scattering states" is a bit lacking in clarity. Tunneling is Ok, and to be expected from all the previous videos and concepts. I haven't got the knack of the concept of quantum scattering (nor the relationship to the ordinary meaning of the word).

  • @meditationtube7572
    @meditationtube7572 6 років тому

    i am struggling to understand the energies and behaviour at E1 and E2, as at some parts of the video , a particle was able to "tunnel through" to the other side without having the necessary energy required... or maybe i simply misunderstood. anyone willing to explain please?

    • @xiaochenjin3963
      @xiaochenjin3963 4 роки тому +1

      Yes because if it's a quantum particle, the wave function is non zero at the region when E