Mechanical Strain Induces Chirality in Non-Chiral Crystals

Researchers from the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) and the University of Oxford have discovered that mechanical strain can induce chirality in non-chiral crystals. This finding, published in the journal Nature, introduces a new method for controlling chirality on demand. Chirality refers to a property where a crystal can exist in two mirror-image forms, often described as left-handed or right-handed. Typically, this property is inherent to the crystal's structure. However, the researchers have demonstrated that applying mechanical stress, such as stretching or compressing, can force a non-chiral crystal into a chiral state. This capability could allow scientists to imprint chiral electronic properties onto materials. Mechanical strain is a widely used technique for modifying material characteristics, commonly employed to alter electrical polarization in piezoelectric materials or induce magnetization in piezomagnetic materials. The new discovery expands the utility of mechanical strain by enabling the controlled induction of chirality, a property previously thought to be fixed by a crystal's intrinsic structure.