Superconductivity emerging from electronic reconstruction

Figure 1: Superconductivity is induced in TiSe2 once holes are released after weakening charge order. The inset shows a picture of the sample in the diamond-anvil pressure cell at tens of thousands atmosphere.

8 July 2024

An exciting new article on superconductivity has been published in Science Advances, co-authored by School of Physics academics Dr. Sven Friedemann, Dr. Felix Flicker, Dr Jonathan Buhot and Dr. Jake Ayres

Superconductivity usually forms when electrons with opposite momentum pair up. The team of Dr. Sven Friedemann now uncovered evidence that in titanium-diselenide, TiSe2, electrons with different momentum pair up to form an unconventional superconducting state.

The team used measurements in high magnetic fields to show that superconductivity emerges exactly when two pockets of electrons with different momentum are present. The second pocket is only released after weakening the charge order that removed these in the first place. To suppress the charge order, they used diamond-anvil pressure cells squeezing the material to more than 50,000 atmospheres. The unconventional pairs of electrons are glued together by remanent vibrations of the charge order that match the momentum balance of the pairs.

The results suggest that superconductivity is often formed from pairs with different momentum across several materials with ordered states.

We are excited by this discovery and to see where our research can go from here!

Further information

To read the full article, please visit:

D. H. Hinlopen et al., “Lifshitz transition enabling superconducting dome around a charge-order critical point,” Science Advances 10 eadl3921 (2024) doi: 10.1126/sciadv.adl3921.