Topological Bloch oscillations

Understand

Bloch oscillations originate from the translational symmetry of crystals.

• These oscillations occur with a fundamental period that a semiclassical wavepacket takes to traverse a Brillouin-zone loop.
• We introduce a new type of Bloch oscillations whose periodicity is an integer ($\mu{>}1$) multiple of the fundamental period.
• The period multiplier $\mu$ is a topological invariant protected by the space groups of crystals, which include more than just translational symmetries.