Fall 2025
By Hongtao Hu
If you’re looking for someone to prove that physics isn’t all blackboards and theory, just ask Emma Codianne. The 2025 Rice grad once assumed physics was mostly abstract math until she stepped into professor Emilia Morosan’s lab and discovered the hands-on experimentation that drives the field forward.
Codianne’s senior thesis focused on a homegrown compound with a name only a physicist could love: Sr₂Mn₃As₂O₂. Known more casually as “2-3-2-2,” it was first synthesized by a Rice graduate student. The compound intrigued researchers because it borrows patterns from two known superconductors and had the potential to become one itself — specifically, a manganese-based superconductor, a rare breed in the scientific world.
Superconductors are materials that, when cooled to a certain temperature, completely lose electrical resistance. This makes them extraordinarily efficient — however, current superconductors are expensive to produce and only work at impractically high temperatures. Codianne aimed to overcome one of those hurdles: accessibility.
“We use the flux growth method to grow our crystals — much like a science experiment in elementary school where you grow sugar crystals,” she said.
Her goal? Transform 2-3-2-2 from a Mott insulator — a material that theoretically should conduct electricity but doesn’t — into a metal. That transition could open the door to superconductivity.
She tried several methods. First was doping: swapping manganese atoms with its neighboring elements like chromium or iron. When that proved difficult, she pivoted to oxygen tuning: changing the oxygen content of the compound to alter its electronic properties.
That pivot paid off. Codianne and her lab successfully transformed 2-3-2-2 from an insulator into a metal. While it didn’t become a superconductor, the result was scientifically thrilling.
“Through oxygen tuning — this is what my senior thesis work was on — the big finding was that we were able to induce this transition,” she said. “At this switch between local to itinerant moment, which is [in middle state transition], is where theorists predict that very cool things are supposed to happen in quantum materials. It could be unconventional superconductivity or something called correlated topology. That’s why we were hoping for the unconventional superconductivity to emerge there in this compound.”
In keeping with its unconventional nature, the material may still hold surprises. And Codianne is well on her way to finding them: She’s headed to Caltech this fall to pursue a Ph.D. in experimental condensed matter physics.
She credits Morosan — and Rice — for helping her find her path.
“I found a really great mentor in Emilia. She helped me figure out what kind of scientist I wanted to be,” Codianne said. “She supported me as I was.”