““You have a number of different ways of organizing that matrix, and we realized our d+d matrix for the orbital space was like a different form of the d+id matrix that describes helium-3 pairing in spin space,” Nica said.
Si said the associations with superfluid helium-3 pairing states have helped him and Nica advance a more complete description of pairing states in both iron-based and heavy-fermion superconductors.
“As Emil and I talked more, we realized the periodic table for superconducting pairing was incomplete,” Si said, referring to the chart physicists use to organize superconducting pairing states.
“We use symmetries — like lattice or spin arrangements, or whether time moving forward versus backward is equivalent, which is time-reversal symmetry — to organize possible pairing states,” he said. “Our revelation was that d+id can be found in the existing list. You can use the periodic table to construct it. But d+d, you cannot. It’s beyond the periodic table, because the table doesn’t include orbitals.””
Well, DUH!
I know, right? Any third grade student knows that 😆