Imaging the Meissner effect in hydride superconductors using quantum sensors
Researchers have developed a new technique for imaging the Meissner effect in hydride superconductors using quantum sensors. By applying pressure to the superconducting material and using a shallow layer of nitrogen-vacancy colour centres implanted within a diamond anvil cell, the researchers were able to perform local magnetometry with sub-micron spatial resolution at high pressures. They applied this technique to characterize a hydride superconductor called CeH9 and observed the dual signatures of superconductivity: diamagnetism characteristic of the Meissner effect and a sharp drop in resistance to near zero. The researchers were also able to directly image the geometry of superconducting regions and found inhomogeneities at the micron scale. This work opens up new possibilities for studying superconducting materials at high pressures and optimizing their synthesis.
Introduction
Pressure is a powerful tool for investigating condensed phases and geophysical phenomena. In this study, researchers focused on the megabar regime, where recent discoveries include high-temperature superconductors. However, many conventional measurement techniques fail at such high pressures. The researchers developed a new method for performing local magnetometry with sub-micron spatial resolution at megabar pressures by using a shallow layer of nitrogen-vacancy colour centres implanted in a diamond anvil cell.
The researchers applied this technique to study a hydride superconductor called CeH9. By performing simultaneous magnetometry and electrical transport measurements, they observed the dual signatures of superconductivity: diamagnetism characteristic of the Meissner effect and a sharp drop in resistance to near zero. They also directly imaged the geometry of superconducting regions and found inhomogeneities at the micron scale.
Experimental Setup
The researchers used a diamond anvil cell with a shallow layer of nitrogen-vacancy colour centres implanted directly within the anvil. They chose a crystal cut that was compatible with the intrinsic symmetries of the nitrogen-vacancy centre, allowing it to function at megabar pressures. By applying pressure to the hydride superconductor CeH9 and using the diamond anvil cell, they were able to perform local magnetometry with sub-micron spatial resolution at high pressures.
The researchers conducted simultaneous magnetometry and electrical transport measurements on the CeH9 sample. They applied an external magnetic field and measured the magnetic response (diamagnetism) and electrical resistance. By mapping both the diamagnetic response and flux trapping, they directly imaged the geometry of superconducting regions and observed inhomogeneities at the micron scale. This technique allowed them to study the Meissner effect in hydride superconductors at high pressures and optimize the synthesis of superhydride materials.
Conclusion
The researchers demonstrated the ability to image the Meissner effect in hydride superconductors using quantum sensors. By applying pressure to the superconducting material and using a diamond anvil cell with implanted nitrogen-vacancy colour centres, they were able to perform local magnetometry with sub-micron spatial resolution at megabar pressures. They applied this technique to study the hydride superconductor CeH9 and observed the dual signatures of superconductivity. This work opens up new opportunities for studying superconducting materials at high pressures and optimizing their synthesis.
Future research in this field could involve further investigations into other hydride superconductors and the development of new techniques for imaging and characterizing superconducting materials.
