In a project partially funded by PALM (the AIMHIP project), physicists from the Laboratoire Aim\u00e9 Cotton (ENS Paris-Saclay\/CNRS\/University Paris-Saclay \u2013 now called LUMIN), in collaboration with CEA and Thales R&T, have overcome this difficulty by observing the response of point defects in the diamond crystal created on the head of one of the two anvils of the cell. These defects were realized by implanting nitrogen ions with a focused ion beam microscope designed with the company Orsay Physics. In the presence of a magnetic field, their luminescence varies, which can be observed by optical microscopy through the anvil. The technique has been validated by the observation of superconductivity in MgB2<\/sub> by optically detecting the Meissner effect, which reflects the expulsion of the magnetic field from a superconducting material.The results of this study provide a much better understanding of the relationship between electronic, magnetic and structural properties as a function of pressure. In particular, it will allow the thorough study of numerous metal hydride compounds. The experimental data will enable the identification of materials whose superconductivity would persist under conditions close to ambient pressure. Finally, this magnetic detection could reveal quantum effects in metallic hydrogen at high pressure, in particular its room temperature superconductivity. The scientific and industrial implications of such a discovery are obviously considerable.<\/p>\n\n\n\n
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