From the Udemy online course "The weird World of Quantum Physics - A primer on the conceptual foundations of Quantum Physics": https://www.udemy.com/quantum-physics/?couponCode=SLIDESHCOUPON

1. The ‚thin film interference‘
l
Waves strike back:
Bragg diffraction and the
de Broglie hypothesis
From the Udemy online course: https://www.udemy.com/quantum-physics/?couponCode=SLIDESHCOUPON

2. Bragg diffraction
Diffraction and interference at atomic crystals
Na
Cl
X-rays

3. Upper plane
Lower plane
Upper plane
Lower plane
X-rays
W. H. Bragg (1862-1942)
W. L. Bragg (1890-1971)
Bragg diffraction
(1913)
Constructive
interference
Destructive
interference

4. Upper plane
Lower plane
Upper plane
Lower plane
X-rays
Bragg diffraction
(1913)
Constructive
interference
Destructive
interference
W. H. Bragg (1862-1942)
W. L. Bragg (1890-1971)

5. X-ray diffraction pattern of a
scandium-zinc crystal
(Ames Lab Physicist Alan Goldman)

6. Louise de Broglie
(1892 – 1987)
The de Broglie hypothesis
(1924)
Traveling ‘wave packets’ according
to the de Broglie hypothesis

7. The de Broglie hypothesis
(1924)
𝐸 = 𝑚𝑐2
𝑝 = 𝑚 𝑣
𝑚 =
𝐸
𝑐2
𝑝
𝑝ℎ𝑜𝑡𝑜𝑛 =
𝐸
𝑐
(𝑣 = c)
Proof:

8. Bohr‘s atomic model
r
𝑒−
𝜆
The de Broglie hypothesis applied to Bohr’s atomic model
„Matter waves“

9. Electron
diffraction
Neutron
diffraction
G.P. Thomson
(1892-1975)
Davisson-Germer Experiment
(1927)
L. Germer (1896-1971)
C. Davisson (1881-1958)
„Matter waves“?
X-rays
electron
neutrons

13. Superposition of 1D waves
nodes
Circular standing wave
Vibrating string 2D standing waveWikimedia Commons