Fields, Universe and Superconductivity

Fields, Universe and Superconductivity

Dr. Takashi Yanagisawa, AIST(National Institute of Advanced Industrial Science and Technology)

There are profound analogies between ideas in particle physics and the corresponding ones in condensed matter physics.  For example, there is a similarity between the Dirac equation and the gap equation of superconductivity.  The Nambu-Goldstone and Higgs modes also play an important role in superconductors.  In particular, multi-condensate superconductors exhibit many interesting properties.  In N-gap superconductors, the U(1)^N phase invariance is spontaneously broken.  This leads to new phenomena, with help of frustrated Josephson effects, such as time-reversal symmetry breaking, the emergence of massless modes and fractionally quantized-flux vortices.  There is also an interesting analogy between quarks and fractionally quantized-flux vortices in superconductors.  Half-flux vortices exist in two-component superconductors under a magnetic field.  They can be interpreted as a monopole, and two half-quantum flux vortices form a bound state connected by a domain wall.