Physics

Bloch oscillations

Quantum tunnelling

Electronic band structure

Superlattice

Resistor

Voltage

Bloch equations

Coalescence (physics)

Band gap

Condensed matter physics

Bloch wave

Quantum mechanics

Zener diode

Astrobiology

Physical Review Letters

Non-Bloch-band theory describes bulk energy spectra and topological invariants in non-Hermitian crystals with open boundaries, where the bulk eigenstates are squeezed toward the edges (skin effect). However, the interplay of non-Bloch-band theory, skin effect, and coherent Bloch dynamics is so far unexplored. In two-band non-Hermitian lattices, it is shown here that collapse of non-Bloch bands and skin modes deeply changes the Bloch dynamics under an external force. In particular, for resonance forcing non-Bloch-band collapse results in Wannier-Stark ladder coalescence and chiral Zener tunneling between the two dispersive Bloch bands.

Non-Bloch-Band Collapse and Chiral Zener Tunneling