HZDR, Fritz Haber Scientists Capture 1st Atom Spin Reversal in Bi2Se3 Crystal
Updated
Updated · Tech Times · May 25
HZDR, Fritz Haber Scientists Capture 1st Atom Spin Reversal in Bi2Se3 Crystal
3 articles · Updated · Tech Times · May 25
Nature Physics published the result on May 12: researchers directly watched angular momentum move between two atomic vibrations in bismuth selenide and saw the rotation flip direction while doubling in frequency.
Terahertz laser pulses drove one lattice mode into circular motion, and a second ultrafast probe tracked the transfer frame by frame inside the Bi2Se3 crystal.
The reversal did not break angular-momentum conservation; the team said bismuth selenide's threefold rotational symmetry makes clockwise and counterclockwise states equivalent, producing an Umklapp-like redirection.
The finding closes a gap left since Einstein and de Haas's 1915 magnetization-rotation experiment and gives researchers a new way to observe and trigger phonon angular-momentum transfer in solids.
That control could help tune magnetic states in quantum materials for qubits, ultrafast memory and storage systems that may eventually need less extreme cooling.
How does a crystal's symmetry make atomic rotations flip and double in speed, challenging our intuition?
Can we now engineer new materials to program atomic-level motion for future quantum technologies?
Can controlling atomic spins in crystals free quantum computers from their extreme cooling needs?
Direct Observation of Atomic Spin Reversal in Bi₂Se₃: A Quantum Leap for Topological Insulators and Future Memory Technologies
Overview
In May 2026, scientists achieved a major breakthrough by directly observing the reversal of atomic spins in the topological insulator bismuth selenide (Bi₂Se₃). Using intense terahertz laser pulses, they set the atoms vibrating in a circular motion and then tracked the transfer of angular momentum with ultrafast stroboscopic lasers. This advanced setup allowed real-time observation of atomic-level changes, resolving a longstanding physics question. The discovery not only deepens our understanding of quantum processes but also opens new possibilities for future technologies that rely on controlling atomic spins.