Fermi's Golden Rule Explained - Two-Level Systems

/ edmundsj
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In this video I begin to derive Fermi's Golden rule, and we talk about two-level systems, what they mean, why they are useful, and how we can model them using quantum mechanics and the Schrodinger equation. We then start to actually plug things in, and we find a differential equation which we ultimately want to solve.
This is part of my graduate series on optoelectronics / photonics, and is based primarily on Coldren's book on Lasers as well as graduate-level coursework I have taken in the EECS department at UC Berkeley.
Hope you found this video helpful, please post in the comments below anything I can do to improve future videos, or suggestions you have for future videos.

[@rachelmcmaster7236]

Dirac notation makes this principle feel so much harder than what it is, ty for clearing it up

[@shakeelurrahman1846]

Good explanation. Thanks

[@bouncyboi3197]

Hi Jordan, I loved the videos. Thanks for putting these up, they're great. For further reading, what textbooks did you source this derivation from?

[@JordanEdmundsEECS]

From Coldren’s book on Laser Diodes primarily

[@SkepticalKhan]

Good explanation

[@AliPMVafa]

Why don't you add more ads? there's some space left yet. it does help learning.

[@JordanEdmundsEECS]

You should know I am nearly incapable of detecting sarcasm xD. I would love to get rid of ads. The next goal on my Patreon channel is to generate enough revenue from there to turn off ads permanently! I'd love your support to help get there: www.patreon.com/edmundsj

[@danielpetka446]

8:02 Engineer 100

[@karmentzalikian2316]

Where is the Fermi's golden rule?

[@alejandrogomezcadavid4612]

there's a second video

[@andrainarandriankoto8957]

I don't understand bro

[@Maestro_presto]

dr.stone

[@physicsperadox7849]

Omg

[@aeroscience9834]

Yeah and that last equation says c1 and c2 are constant in time. Which we already know since you just assumed psi 1 and 2 were eigenstates of H.... This was a poorly done video, You aren’t doing what I think you are trying to do, which was to have psi eigenstates without light and then have H include light interaction term.

[@JordanEdmundsEECS]

That’s in the next video. This video was to go through the mechanics of how to set up the equations, and in the next video we include the interaction term. Psi 1 and psi 2 are eignenstates of H, and we will be expanding the system with the coupling term as a linear combination of these two states with slowly-varying c1 and c2. Most EEs in optoelectronics are not familiar with how to do this so I’m going through the simpler case of no interaction term first.

[@bouncyboi3197]

Gonna disagree with you here. It's a well done video, that just wasn't the point of this video.