superfluidity summary

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Below is the article summary. For the full article, see superfluidity.

superfluidity, Unusual property of liquid helium cooled below −455.75 °F (−270.97 °C). At such low temperatures, helium exhibits an enormous rise in heat conductivity and rapid flow through capillaries or over the rim of its container. To explain such behaviour, the substance is described in terms of a “two-fluid” mixture model consisting of normal helium and superfluid helium. In normal helium the atoms are in excited states (see excitation), whereas in superfluid helium they are in their ground state. As the temperature is lowered below −455.75 °F, more of the helium becomes superfluid. It is assumed that the superfluid component can move through the container without friction, thereby explaining the unusual behaviour.

Lev Davidovich Landau Summary

Lev Davidovich Landau was a Soviet theoretical physicist, one of the founders of the quantum theory of condensed matter whose pioneering research in this field was recognized with the 1962 Nobel Prize for Physics. Landau was a mathematical prodigy and enfant terrible. His schooling reflected the