Relativistic quantum mechanics

The Dirac equation’s exact hydrogen levels and their fine structure, and Klein’s paradox: how Dirac and Klein-Gordon particles scatter off a potential step taller than twice their rest energy.

The Dirac equation and the fine structure of hydrogen

The Dirac equation and the fine structure of hydrogen

Klein’s paradox: relativistic particles at a tall potential step

Klein's paradox: relativistic particles at a tall potential step