Ferromagnetic Superconductors: Who ordered this strange matter? Kevin S. Bedell Department of Physics Boston College Ferromagnetic metals were discovered early on by the ancient Greeks. Over the centuries we have learned to harness these materials and they have been most valuable in a variety of applications, magnetic recording devices and the magnet on the beer bottle opener, to name a couple of the most important ones. A couple of millennia later in 1911, superconductivity was discovered by Kamerlingh Onnes. Things started to progress more rapidly after that when Meissner and Ochsenfeld in 1933 discovered that a superconductor expelled a magnetic field. We also know that a sufficiently large magnetic field will suppress superconductivity. From this brief and early history of magnetism and superconductivity, it would appear that the two effects might never get together. Fortunately, the story of this affair, built upon mutual repulsion, does not end here; there is a new chapter! The new chapter was written when superconductivity and ferromagnetism were found to co-exist on the same side of the phase diagram for some ferromagnetic metals. To understand these materials we must first examine some basic notions of quantum mechanics, including, exchange and the Pauli Principle. In this talk I will describe some new results for the phase diagram of the superconducting ferromagnetic metal, UGe2. I will show that there is a simple physical model that can explain the main features of this material, including, among other things, a line of weak first order transitions ending at T = 0 at what is a “classic” example of a triple point, which we refer to here as a quantum triple (or tri-critical) point, QTP.