Lecture Physics A2: Fundamental of Quantum Mechanics - PhD. Pham Tan Thi present the content diffraction of light/electron by one slit, double-slits experiments for electrons, wave-particle duality, De Broglie’s hypothesis, for a non-relativistic free particle, . | Fundamental of Quantum Mechanics Pham Tan Thi . Department of Biomedical Engineering Faculty of Applied Sciences Ho Chi Minh University of Technology Quantum Mechanics Diffraction of Light Electron by One Slit Double-slits Experiments for Electrons Wave-like character of electrons Wave-Particle Duality Energy in Energy out A beam of light can be thought as . . a flux of particle . an electromagnetic wave Newton Planck Einstein Huygens Maxwell Hertz Electric Field Wavelength λ Zero mass speed c 3 x 108 m s Direction of propagation Energy carried by each particle h x 10-34 Planck c λν Dispersion relation ν frequency 1 T period Free space Particle Photon Wave Electromagnetism - Photoelectric Effect - Interference - Compton Effect - Diffraction de Broglie s Hypothesis Light can behave like a particle and Matter Electron can behaves like a wave Energy of Photon by Special Relativity E pc Energy of Photon by Planck s theory E h de Broglie s wavelength h p Wave if λ gt Scale It turns out that everything s kind of mixed together at the fundamental microscopic scale. For a Non-relativistic Free Particle Momentum is p mv here is v is the speed of the particle Total energy of a free particle E is kinetic energy h h h B p p mv 2mE p2 mv 2 E K 2m 2 Bullet m kg v 1000 m s 36 B 10 m What is the de Broglie s Wavelength of an Electron What is the de Broglie s wavelength of an electron moving at x 106 m s What is the de Broglie s Wavelength of an Electron What is the de Broglie s wavelength of an electron moving at x 106 m s Now this is really really fast million meters per second. But it s not relativistic. It s is still slow compared to the speed of light so we can still do everything fairly classically. 31 p mv 10 106 kg m s 2 10 24 34 24 10 h p 10 2 10 10 m This is important number. This speed is a kind of average speed of an electron in ground state of hydrogen. Accelerated What is the de Charges Broglie s electrons .
