Nature Communications, Published online: 12 June 2026; doi:10.1038/s41467-026-74221-7 The authors present a theoretical mechanism for the recently-observed pair density modulation in exfoliated flakes of the iron-based superconductor FeTe0.55Se0.45. The mechanism is based on the appearance of a nematic mixed s± + d superconducting phase in a system with broken glide mirror symmetry.