Condensed Matter II: Soft Condensed Matter

1
Condensed Matter IISoft Condensed Matter

• Chaikin and Lubenskys book
• Begin with Chapters 1 to 5
• Overview
• Structure and Scattering
• Thermodynamics and Statistical Mechanics
• Mean-field theory
• Field theories, critical phenomena, and
  renormalization group
• Experimental in approach
• Powerpoint versus blackboard
• Homework problems and grading
• Adjust topics as go along
• Will help if you read Chaikin and Lubensky as we
  go along

1-15-08
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Condensed Matter

• Solids
• Crystals
• Glasses (window)
• Aggregates
• Granular media

Ice quartz copper sulfate quartz Wikipedia
Ice Crystals, Crystals, Diffusion Limited
Aggregation, Sand
3

• Solids
• Quasicrystals (Al-Mn alloy)
• Liquid crystals (my computer screen)
• Liquids
• Gases
• Whats the difference between solids, liquids,
  and gases?
• (List)

4
Parameter Space
Gas

• Other Parameters
• Pressure
• Number/composition
• Magnetic Field
• Electric Field
• Etc.

Liquid
Temperature
Solid
5
Phase Diagrams
At one atm of pressure, water changes from solid
to liquid to gas as a function of temperature At
0.25 atm of pressure, water changes from a solid
to a gas as a function of temperature
Wikipedia Commons
6
Order Parameters and Symmetry
Gas rotational and translational symmetry of
free space
Temperature
Symmetry
Solid (crystal) discrete set of translations
and rotations are allowed

• Break or lower the symmetry as move from gas to
  solid
• Order parameter describes the change in symmetry
• Example Rotations and square lattice (discuss)
• Space Groups describe crystalline symmetry

7
Liquid/Gas Transition is a Special Case
At 2300 atm of pressure, water changes from a
solid to a liquid as a function of temperature
(1 atm is about 105 Pascals, note logarithmic
scale for pressure) Critical point Location in
phase diagram where distinction between liquid
and gas is lost. Order parameter density.
Theres no real difference in symmetry between
liquid and gas.
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Ice
http//www.nyu.edu/pages/mathmol/textbook/hbond_ic
e.gif
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Ice I
Comment Hydrogren bonding is actually
disordered.
http//www.lsbu.ac.uk/water/ice1h.html
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Intermission

• Bonding I (intro)
• Van der Waals
• Hydrogen Bonding
• Covalent (directional)
• Metallic
• Ionic