 |
| Illustration of the principle of optical resonance, where thin sheets of iron can be made transparent using X-ray lasers |
Transparency is generally a property of a material's density or crystal structure, and varies depending on the wavelength of light. However, transparency can also be achieved by exploiting quantum interference between energy level transitions in atoms. Up until now, such transparency has been confined to optical wavelengths, due to the typical energies of atomic transitions.
Transitioning between energy levels within atomic nuclei (instead of electron transitions) involves much higher energies, corresponding to hard X-ray frequencies. Ralf Röhlsberger, Hans-Christian Wille, Kai Schlage, and Balaram Sahoo of the Deutsches Elektronen-Synchrotron (DESY) in Germany have induced transparency in iron-57 nuclei, using an X-ray laser to drive the nuclei to resonance. The experiment not only made the iron nuclei nearly vanish, but also slowed the X-ray photons to a small fraction of their usual speed. This result holds out the tantalizing possibility of quantum optics in the nuclear regime, providing us new ways of manipulating light at far higher energies than have previously been possible.
The basic technique is termed electromagnetically induced transparency (EIT). It involves balancing the absorption of light by an atom or nucleus with a corresponding emission, which makes it appear as though the material is nearly absent.
Transitioning between energy levels within atomic nuclei (instead of electron transitions) involves much higher energies, corresponding to hard X-ray frequencies. Ralf Röhlsberger, Hans-Christian Wille, Kai Schlage, and Balaram Sahoo of the Deutsches Elektronen-Synchrotron (DESY) in Germany have induced transparency in iron-57 nuclei, using an X-ray laser to drive the nuclei to resonance. The experiment not only made the iron nuclei nearly vanish, but also slowed the X-ray photons to a small fraction of their usual speed. This result holds out the tantalizing possibility of quantum optics in the nuclear regime, providing us new ways of manipulating light at far higher energies than have previously been possible.
The basic technique is termed electromagnetically induced transparency (EIT). It involves balancing the absorption of light by an atom or nucleus with a corresponding emission, which makes it appear as though the material is nearly absent.
Ars Technica: Forget transparent aluminum-researchers make iron invisible to X-rays
No comments:
Post a Comment