A topological insulator is a material whose interior behaves as an electrical insulator while its surface behaves as an electrical conductor, meaning that electrons can only move along the surface of
Two curves or said to be homotopically equivalent if they can be smoothly deformed into one another. Every loop on the 2-sphere can be smoothly deformed into a single point, hence all looops on the 2-sphere are homotopically equivalent.
In condensed matter physics, a quantum spin liquid is a phase of matter that can be formed by interacting quantum spins in certain magnetic materials. Quantum spin liquids are generally characterized
Herbertsmithite, the mineral whose ground state was shown to have QSL behaviour