quantum electronic devices tagged posts

These images show the orbital paths of electrons trapped within a circular region within graphene. In the classical orbit (top image), an electron that travels in a complete circuit has the same physical state as when it started on the path. However, when an applied magnetic field reaches a critical value, (bottom image), an electron completing a circuit has a different physical state its original one. The change is called a Berry phase, and the magnetic field acts as a switch to turn the Berry phase on. The result is that the electron is raised to a higher energy level.
Credit: Christopher Gutiérrez, Daniel Walkup/NIST