The concepts of 'spontaneous symmetry breaking', 'generalized rigidity', and 'collective modes' play an important role in theoretical physics. Indeed much of the phenomenology of condensed matter can be understood in terms of these concepts within the framework of quantum mechanics and statistical mechanics. The story I tell is a synthesis of ideas drawn from hydrodynamics, atomic and optical physics, combined with the dynamical manifestations of spontaneous symmetry breaking in superfluid 3He (the light isotope of Helium). The phenomena I describe include the experimental discovery of transverse current waves ('transverse sound') that propagate in the superfluid phase of liquid 3He as a result of the coupling of transverse currents to a collective mode of superfluid 3He with spin J=2.
The Sounds of Broken Symmetry in Superfluid Helium
School of Physics and Astronomy
James Clerk Maxwell Building
Peter Guthrie Tait Road