approach based on the Logarithmic Schrödinger equation; it suggests the Gaussian-like behaviour of the element's interior density and interparticle interaction potential. The long-wavelength part is the quantum many-body theory of such elements which deals with their dynamics and interactions. The approach provides a unified description of the phonon, maxon and roton excitations, and has noteworthy agreement with experiment: with one essential parameter to fit one reproduces at high accuracy the Landau roton spectrum, sound velocity and structure factor of superfluid helium-4. This model utilizes the general theory of quantum Bose liquids with logarithmic nonlinearities which is based on introducing a dissipative-type contribution to energy related to the quantum Everett–Hirschman entropy function. See also Douglas D. Osheroff Large Hadron Collider London moment Polariton superfluid Quantum acoustics Quantum gyroscope Superdiamagnetism Superfluid film Timeline of low-temperature technology References Further reading Antony M. Guénault: Basic superfluids. Taylor & Francis, London 2003, D.R. Tilley and J. Tilley, Superfluidity and Superconductivity, (IOP Publishing Ltd., Bristol, 1990) Department of Energy Office of Science: Superfluidity Hagen Kleinert, Gauge Fields in Condensed Matter, Vol. I, "SUPERFLOW AND VORTEX LINES", pp. 1–742, World Scientific (Singapore, 1989); Paperback (also available online) James F. Annett: Superconductivity, superfluids, and condensates. Oxford Univ. Press, Oxford 2005, London, F. Superfluids (Wiley, New York, 1950) Philippe Lebrun & Laurent Tavian: The technology of superfluid helium External links Helium-4 Interactive Properties http://web.mit.edu/newsoffice/2005/matter.html Liquid Helium II,Superfluid:demonstrations of Lambda point transition/viscosity paradox /two fluid model/fountain effect/creeping film/ second sound. Physics Today February 2001 superfluid hydrodynamics Superfluid phases of helium The Hindu article on superfluid states Video including superfluid helium's strange behavior Liquid helium Bose–Einstein condensates Fluid dynamics Emerging technologies Superfluidity