Researchers Observe 1+1=-1 Angular Momentum Flip in Bismuth Selenide Crystal
Updated
Updated · SciTechDaily · May 17
Researchers Observe 1+1=-1 Angular Momentum Flip in Bismuth Selenide Crystal
1 articles · Updated · SciTechDaily · May 17
Bismuth selenide experiments gave the first direct view of angular momentum moving between crystal-lattice vibrations and reversing direction during the transfer.
Terahertz laser pulses drove one lattice mode into circular motion and probed a coupled mode, revealing that the flip still preserves angular momentum because of the crystal’s rotational symmetry.
The team describes the effect as a lattice-angular-momentum version of an Umklapp process: two units combine into a vibration at twice the frequency but with opposite rotation.
Nature Physics published the study on May 12, and the researchers say it sharpens understanding of how magnetism emerges in solids and could aid ultrafast control of quantum materials, memory devices and future information technologies.
If atomic spins can suddenly reverse, what other fundamental laws of physics have we misunderstood?
A quantum '1+1=-1' effect was just found. Could it make our computers a thousand times faster?
Angular Momentum’s Unexpected Flip in Bi₂Se₃: First Direct Evidence and Implications for Quantum Technologies
Overview
On May 12, 2026, researchers from Berlin, Dresden, Jülich, and Eindhoven made a groundbreaking discovery by directly observing how angular momentum moves and unexpectedly reverses within a bismuth selenide crystal lattice. This surprising 'flip,' described as '1 + 1 = -1,' revealed new details about how angular momentum spreads in solids. The experiment gave scientists a clearer understanding of how magnetism forms and stabilizes in quantum materials. This breakthrough not only deepens our knowledge of fundamental physics but also opens exciting new possibilities for developing advanced technologies based on quantum phenomena.