Liquid crystals have orientational order described by a headless director n̂. Topological defects carry charge ±½: the director rotates by ±π around a defect core. Defects of opposite charge attract and annihilate; same-sign repel. Click to place +½ (gold) or −½ (blue) defects.
Click on canvas to place defects. Defects with opposite charges attract and annihilate.