Breakthrough in Quantum State Control within Helium Atoms

An international team of scientists led by the University of Freiburg's Institute of Physics has successfully generated and directly controlled a hybrid electron-photon quantum state in helium atoms. This groundbreaking research has been published in the prestigious journal Nature.

Intense light fields can create entirely new quantum states. When electrons are confined within atoms, their energy levels are typically fixed at discrete levels determined by the atom itself. However, when atoms are exposed to extremely intense laser beams, these energy levels can be altered, giving rise to hybrid electron-photon states.

This phenomenon typically occurs at laser intensities ranging from 10 to 100 terawatts per square centimeter. To generate and manipulate these unique quantum states, laser pulses must reach such intensities within just a few femtoseconds.

In their experiment, scientists utilized a femtosecond free-electron laser to generate high-intensity extreme ultraviolet light with wavelengths of less than 100 nanometers, a crucial factor in controlling the electron states within helium atoms.