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Figure 2: The theoretical studies from JQI researchers and collaborators indicate that by loading ultra-cold fermionic atoms into higher orbitals of a double-well optical lattice, a topological semi-metal state will arise. If the particles are allowed to interact, this novel state of matter turns into a topological insulator exhibiting quantum Hall physics due to the spontaneously-generated rotation. Here, each atom is represented by what looks like two dumbbells that cross. This is because this particular topological state is a property of higher orbitals and physicists represent orbitals with different shapes. To date, much of the atom-optical lattice experiments focused on physics of the lowest orbital or "s" band, represented by a sphere. Recently, scientists have been exploring physics associated with higher orbitals, like the dumbbell shaped "p" orbitals shown here.