“Spontaneous Symmetry Breaking andthe phases of Superfluid 3He”
One of the key features of spontaneous symmetry breaking in condensed matter and quantum field theory is the emergence of new elementary quanta – phonons in crystalline solids, magnons in ferromagnets, the Higgs and gauge bosons of the Standard Model. In the latter example, the BCS theory of superconductivity played a role in the development of theories of the mass spectrum of elementary particles. I discuss the theoretical ideas of Nambu,Jona-Lasinio, Anderson and Higgs for the spectrum of Bose quanta in BCS-typetheories. These ideas are realized by the discoveries of Higgs Bosons at the LHC and in superconducting matter. In the latter case I highlight the discoveries of Nambu-Goldstone and Higgs Bosons in superfluid 3He, the light isotope of Helium.The superfluid phases of 3He are also paradigms for topologically ordered quantum matter, the signatures being a spectrum of massless Majorana and Weyl particles confined on lower dimensional boundaries and interfaces. Theoretical ideas and predictions are driving a new generation of experiments to detect and control these novel excitations.
Host: John Davis