The piezochiral effect
2026-07-29
Chirality is a pervasive property of matter that underpins many important phenomena across physics 1 , chemistry 2 and biology 3 . Given its broad importance, the development of protocols for rational control of chirality in solid-state systems is highly desirable, especially if this effect can be tuned continuously and in two directions. Yet, this goal has remained elusive owing to the absence of a universal conjugate field that couples linearly to this structural order 4–6 . Here we introduce the piezochiral effect, which enables control of chirality through mechanical strain. We show by symmetry analysis that uniaxial strain induces chirality in a broad class of achiral crystals that host fragments of opposite chirality within each unit cell 7,8 , an effect that has so far remained unrecognized. The strain-induced handedness can be tuned either by changing the strain direction or by switching between compressive and tensile strain. We experimentally verify this effect in AgGaS 2 , using measurements of the optical activity under strain. Our discovery establishes a new scheme for chirality control, with potential applications that range from spintronics to asymmetric catalysis, and enantioselective interactions in biosystems.