Graduate Lecture Series 29 June – 3 July, 2009 Prof Ngee-Pong Chang

Graduate Lecture Series29 June – 3 July, 2009

Prof Ngee-Pong Chang

Quantum PhysicsUnderlying

Modern Technology

Lecture 1Quantum Physics Overview

A SCANNING microscope image of platinum-lace nanoballs. Liposomes aggregate, providing a foamlike template for a platinum sheet to grow.

NanoScience

Nano-scale Tic-Tac-Toe scratched into polycarbonateLine widths are ~ 40 nm

5 x 5 mm image

50 nm Z scale

Quantum Dots

10-6 m

Max Planck

1858 - 1947

A plaque at Humboldt University, Berlin, commemorating Max Planck as "discoverer of the elementary quantum of action h," who "taught in this building" from 1889 to 1928

Old-fashioned Fireplace

Superlog

Log in the Fireplace

Progress of Technology

:

Replacing the real &

messy

with

theclean &

convenient

Blackbody Radiation

λmax dependence on T

Wien’s Law 1893

1864 - 1928

Rayleigh-Jeans Law 1900

1842 - 1919 1877 - 1046

Blackbody Radiation

Birth of Quantum Physics

M. Planck,

Annalen der Physik,

vol 4, 553 (1901)

What is quantized ?

Ideal Blackbody

Standing Wavecondition

Polarization vector

2 Polarization states

Standing Waves in a Cavity

or

octant

Standing WaveCondition

Boltzmann Probability Distribution

Average Energy

Equipartition Theorem

Ultraviolet Catastrophe !

Rayleigh-Jeans Law 1900

1842 - 1919 1877 - 1046

Classical

Quantum

Planck Quantization

Planck Blackbody Radiation Formula

Blackbody Radiation

Birth of Quantum Physics

M. Planck,

Annalen der Physik,

vol 4, 553 (1901)

Relation to Wien’s Constant

Peak Intensity condition

Wien’s Constant

Cosmic Background Radiation

1997

Far Infra-Red Absolute Spectrophotometer

Our Universe as a Blackbody

2.7280 ± 0.0001 K BLACKBODY

FIRAS DATA

What is quantized ?

Albert Einstein

1879 - 1955

Einstein’s Photon Hypothesis (1905)

Energy

Momentum

Niels Bohr

1885 - 1962

Bohr Model of the Atom

Angular Momentum Quantization

1913

Angular Momentum Quantization

Bohr radius

Bohr Model of the Atom

Bohr Model of the Atom

Compton wavelengthof electron

Fine StructureConstant

Bohr Radius

Hydrogen 1s level

rst.gsfc.nasa.gov

Einstein’s Photon Hypothesis

Energy

Momentum

Prince Louis-Victor Pierre Raymond de Brőglie

(1892 – 1987)

1924

W. Heisenberg

1901 - 1976

Uncertainty Principle

A convenient back-of-the-envelope way to keep

track of the energy levels of quantum wells, and

quantum dots.

E. Schrődinger

1887 - 1961

Schrődinger Equation

Stationary State

Time-Independent Schrődinger Equation

Classical Equations of Motion

Ehrenfest Theorem

Average Expectation Values

Paul Ehrenfest

1880 - 1933

Max Born

1882 - 1970

Electron build up

over time

Double Slit Experiment

Ehrenfest with his students

Dieke, Goudsmit, Tinbergen, Ehrenfest, Kronig, Fermi.

George Uhlenbeck

1900 - 1988

S. Goudsmit

1902 - 1978

Note to Goudsmit by L.H. Thomas Mar 25, 1926

Wolfgang Pauli

1900 - 1958

Pauli & Bohr & a spinning top

Dirac Equation

Non-relativistic limit

Spin-Orbit Coupling

Origin of Spin-Orbit Coupling

Electron moving in a static E field sees a magnetic field, B :

Electron spin precesses around this B field according to the magnetic moment interaction

Electron orbiting around nucleus

In electron rest frame, nucleus orbiting around electron

Enrico Fermi

1901 - 1954

Paul Dirac

1902 - 1984

Fermi Sea

Fermi-Dirac Distribution

A. Piccard, E. Henriot, P. Ehrenfest, Ed. Herzen, Th. De Donder, E. Schrödinger, E. Verschaffelt, W. Pauli, W. Heisenberg, R.H. Fowler, L. Brillouin,

P. Debye, M. Knudsen, W.L. Bragg, H.A. Kramers, P.A.M. Dirac, A.H. Compton, L. de Broglie, M. Born, N. Bohr,

I. Langmuir, M. Planck, M. Curie, H.A. Lorentz, A. Einstein, P. Langevin, Ch. E. Guye, C.T.R. Wilson, O.W. Richardson

1927

Solvay

Conf

EinsteinPlanck

PauliHeisenbergSchrodinger

BohrDirac

Bose – Einstein Statistics

1924

1894 - 1974 1879 - 1955

Kammerlingh Onnes 1853-1926

On the Sudden Rate at Which the Resistance of Mercury Disappears

Communications of the Leiden Laboratory, 1911

Meissner Effect

1933

Walther Meissner1882 - 1974

Robert Ochsenfeld

Quantization of Flux