Mod-04 Lec-14 Tunneling through a Barrier

[@doutormanhattan5680]

I spent a lot of time looking for a teacher like that. I'm glad I found you. I knew it was going to be an indian guy. I also watch For The Love of Physics videos.

[@josephmcmahon4139]

more helpful than my prof I have for Quantum Mechanics I at Georgia Tech. I'm studying for the final right now and you cleared up a lot of confusion. Thank You

[@wankmaster69]

Don't forget to increase playback speed to 1.5 lol

[@salu30000]

@@wankmaster69 correction - 2x , he could actually complete the lecture in half the time he had taken , if he had wanted

[@KasperKubica]

I love this guy. He makes everything so simple and lucid.

[@tayyabanawaz5265]

Want such a teacher to teach quantum mechanics😢😢

[@Khalil9497]

Thank you very much, i'm so thankful

[@elamvaluthis7268]

Very nice explanation beyond doubt.

[@zarinamingazheva482]

Thank you for the helpful lecture. Should be the equation at the time 27:34 A*(1-ik/kappa)+B(1+ik/kappa)=2C?

[@kontiimanalatit8987]

Yes

[@Mohitmccall]

27:35 sir when we added up that two eq's then RHS should be 2C !?

[@srijanraghunath4642]

No it should actually be 2D. After he divided by kappa u distribute negative and then when u add equations C cancels but the two Ds get added together

[@salu30000]

@@srijanraghunath4642 yes you are right

[@sunnypala7629]

Great respect for you sr.

[@sunnypala7629]

Sr brilliantly explained

[@DeepikaGupta4721]

This Video is really helpful. Thank you so much Sir...

[@shanmukarao7668]

At 8:34 professor said last lecture can anyone tell me where is that last lecture plz send me the link

[@satyajitprasad6872]

Search core QM nptel in ytb

[@TravelwithAmit-yy7rn]

there is a little mistake @28:01

[@vinayrana610]

well explained ajoy sir

[@juniedtazrian593]

how the transmission probability changes with the change of a moving microscopic particle?

[@surajpradhan8606]

So, quantum mechanics allows a particle to have negative kinetic energy ?

[@entrainer6709]

No then eigenvalu of hamiltonian operator for kinetic energy will be - ve

[@surajpradhan8606]

Jitendra Prajapat
Yes, the total energy can be negative which refers to a bound state. Here, the kinetic energy is not negative but less than the potential barrier. And QM says it has some finite probability of tunneling through the barrier. How amazing !

[@entrainer6709]

@@surajpradhan8606 thnx a lot of sir kaha se ho plz

[@surajpradhan8606]

@@entrainer6709
Sambalpur, Odisha

[@kanhaiyalal-kv2vg]

even negative kinetic energy also allowed in qm

[@ruchijha6162]

if all the energy gets reflected from where does the energy for evanescent wave come from in ftir?

[@PhysicsMath]

E-t uncertainty for short time..

[@kanhaiyalal-kv2vg]

@@PhysicsMath No,in classical mechanics uncertainty not allowed

[@ashugoyal2231]

In the last lecture you have taken C constant with e to the power positive something and here you have taken constant C with e to the power of negative something.
Pls explain this.
Anyone??

[@nicholeoneill4085]

The positive and negative exponents reflect the direction of propagation or decay. Here he is using Ce^-kx to denote the decay of the wave once it's within the barrier. I don't know what the last lecture was or the equation, but I'm willing to bet it was describing a wave that propagated through a single wall and is now traveling in the positive x direction. If you go back to when he derives psi for region II (in this video) he explains why the exponent is negative (after he discusses evanescent waves).

[@elamvaluthis7268]

Transcend/go beyond.

[@ruby4244]

Thankyou sir great

[@Anonymous-do6ck]

sir how is this possible that v0 is greater than energy E?

[@surajpradhan8606]

jarur Kandulna V0 greater than E is not surprising as it is possible. But, how quantum mechanics allows a particle to have a negative kinetic energy is amazing.

[@ashkaralam845]

Thanks you sir

[@007acreed]

Thanks Sir