Condensed matter physics

Condensed Matter referred to in the natural sciences, the solid and liquid state as opposed to gas and plasma.

Condensed Matter Physics

The physics of condensed matter differs due to the mutual interaction of blocks of matter significantly from the free particles ( elementary particle physics, nuclear physics ). The theoretical description is based on the many-body theory. Many phenomena such as deformability, magnetic order, or electrical conductivity back to a certain order of the interaction between the building blocks of condensed matter. They should therefore be treated in condensed matter quite different from free particles or occur in the first place on in condensed matter.

The treatment of the condensed matter physics is characterized in that the large number of particles which make up the system to be described, excluding a basic solution of the various equations of motion. In place of a description of the states of the individual particles of the system instead statements about frequencies (or normalized to the number of possible states: probabilities ) that certain states of arbitrary particles occur in the system.

In solids are particularly correlations of various types of interest ( for example, long-range correlation of the atomic positions itself crystalline lattice, or correlation of the electron spins → magnetic order such as ferromagnetism and antiferromagnetism ).

An important tool in the treatment of deformation in condensed matter represents the continuum mechanics

The concepts of condensed matter physics are widely applied across the range of solid and liquid matter out (examples: risk management, insurance statistics, neural networks ).

Subjects

Solid State Physics

The solid-state physics deals with the physics of matter in the solid state. Of particular importance are crystalline solids, which are those that have a translational symmetry ( periodic ) structure, since this translational symmetry the treatment of many physical phenomena drastically simplified or even at all possible. Therefore, the application of the model of the ideal crystal lattice is often even when the condition of the frequency is very limited, is satisfied, for example, only very locally. The deviation from strict periodicity is taken into account by corrections.

  • The physics of crystalline solids deals with solids, which have a periodic structure. The crystal structure represents the static periodic order in the crystalline solid state, see in particular crystallography.
  • The lattice vibrations describe the dynamics in the crystalline order. Your description often used the model of quasi-particles. In this lattice excitations are called phonons.
  • The returning to the electron shell of the regularly arranged atoms properties lead to the band model and band structure, making their parameters various macroscopic properties ( optical, etc. ) can be calculated.
  • The magnetic order represents the static order of the magnetic moments in the solid state ( diamagnetism, paramagnetism, ferromagnetism, antiferromagnetism, spin density waves, magneto-optics, etc.).
  • The magnetic excitations describe the dynamics of the magnetic order. The corresponding quasiparticles are called magnons.
  • The physics of amorphous solids deals with solids, which have no long-range order. glass
  • Supercooled melt
  • The surface physics is a special case of interfacial physics at interfaces to vacuum.

Physics of Fluids

The Physics of Fluids deals with matter in the liquid state. The components of the liquid have a high mutual Moving on ( translation and rotation).

Soft Condensed Matter

The concept of soft condensed matter one summarizes substances that differ in two essential features of the " hard matter " of crystalline solids:

  • On the one hand there is the characteristic length scale of the order of molecules, that is in a range between 1 nm and 1 micron. The basic building blocks of soft matter thus have a complex substructure.
  • On the other hand, these devices are subject to strong thermal fluctuations, so that the relevant energy scale is set by the thermal excitation energy. The energies occurring here are thus significantly smaller ( typically a few meV ) than in hard matter where they range from a few electron volts (eV ) are.

For soft matter are mainly amorphous substances which have no long-range crystalline order, such as polymers, liquid crystals, colloids and membranes.

Systems ( exemplary)

  • Alloys
  • Metals
  • Semiconductor
  • Insulators
  • Spin- glasses
  • Polymers
  • Membranes
  • Superlattice

Phenomena ( examples)

  • Effective mass ( quasiparticles )
  • Ferroelectricity
  • Electrical conductivity
  • Superfluidity
  • Superconductivity
  • Magnetism
  • Hall effect, quantum Hall effect
  • Photo line
  • Kondo effect
  • RKKY coupling
  • Phase transitions
Brillouin-Zone Atomic physics Actuarial science Dynamics (physics) Petrographic microscope Wafer (electronics) Spin glass Effective mass (solid-state physics) RKKY interaction Charles Kittel
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