Coexisting Electronic Smectic Liquid Crystal and Superconductivity in a Si Square-Net Semimetal
Phys. Rev. Lett. 136, 076001 – Published 18 February, 2026
DOI: https://doi.org/10.1103/qfqm-qp82
Abstract
Electronic nematic and smectic liquid crystals are spontaneous symmetry-breaking phases that are seen to precede or coexist with enigmatic unconventional superconducting states in multiple classes of materials. In this Letter we describe scanning tunneling microscopy observations of a short ranged charge stripe (smectic) order in NaAlSi, whose superconductivity is speculated to have an unconventional origin. As well as this we resolve a clear spatial modulation of the superconducting gap amplitude, which arises due to the intertwined superconducting and smectic orders. Numerical calculations help to understand the possible driving mechanism as a suppression of kinetic energy on the Fermi surface formed in part by two large, flat-topped hole pockets of -orbital character.
