Lev Landau

Soviet theoretical physicist (1908–1968)

thumb|right|Helium#Helium II|Helium II will "creep" along surfaces in order to find its own level—after a short while, the levels in the two containers will equalize. The [[Rollin film also covers the interior of the larger container; if it were not sealed, the helium II would creep out and escape.]] thumb|right|The liquid helium is in the superfluid phase. A thin invisible film creeps up the inside wall of the bowl and down on the outside. A drop forms. It will fall off into the liquid helium below. This will repeat until the cup is empty—provided the liquid remains superfluid.

matrix describing a quantum system in a pure or mixed state, a statistical mixture of quantum states

thumb|Roton dispersion relation, showing the quasiparticle energy E(p) as a function of momentum p. A quasiparticle with momentum generated in the local energy minimum is called a roton. In theoretical physics, a roton is an elementary excitation, or quasiparticle, seen in superfluid helium-4 and Bose–Einstein condensates with long-range dipolar interactions or spin-orbit coupling. The dispersion relation of elementary excitations in this superfluid shows a linear increase from the origin, but exhibits first a maximum and then a minimum in energy as the momentum increases. Excitations with mom

superconductivity theory

quantum account of metals and other matter in terms of interacting fermions

thermodynamic potential

quantum phenomenon

effect of damping of longitudinal space charge waves in plasma or a similar environment

probability distribution

quantum mechanical phenomenon in which heat transfer occurs by wave-like motion

describing the precessional motion of magnetization in a solid

result in general relativity

a theory that Lev Landau introduced in an attempt to formulate a general theory of continuous (i.e., second-order) phase transitions

selection rule that a massive particle with spin 1 cannot decay into two photons

formula for the probability that a system will change between two energy states.

reduction of the bremsstrahlung and pair production cross-energy phenome

Collective excitation in a Fermi liquid

The study of hydrodynamic-like systems which demonstrate quantum mechanical behavior