Detecting superconductivity in the high pressure hydrides and metallic hydrogen from optical properties

Abstract

We present a new technique for measuring the critical temperature Tc in the high pressure, high Tc electron-phonon-driven superconducting hydrides. This technique does not require connecting leads to the sample. In the multiphonon region of the absorption spectrum, the reflectance mirrors the temperature variation of the superconducting order parameter. For an appropriately chosen value of photon energy of order twice the gap plus 1.5 times the maximum phonon energy, the temperature dependence of the reflectance varies much more rapidly below T=Tc than above. It increases with increasing temperature in the superconducting state while it decreases in the normal state. Examining the temperature dependence of the reflectance at a fixed photon energy, there is a cusp at T=Tc which provides a measurement of the critical temperature. We discuss these issues within the context of the recently observed metallic phase of hydrogen.

(5 pages, 5 figures)

References in corpus (10)

• Observation of the Wigner-Huntington Transition to Solid Metallic Hydrogen
• Hydrogen sulphide at high pressure: a strongly-anharmonic phonon-mediated superconductor
• What superconducts in sulfur hydrides under pressure, and why
• Cubic H${}_3$S around 200 GPa: an atomic hydrogen superconductor stabilized by sulfur
• Spectroscopy of H${}_3$S: evidence of a new energy scale for superconductivity
• Anharmonic effects in atomic hydrogen: superconductivity and lattice dynamical stability
• Comparison of pressurized sulfur hydride with conventional superconductors
• Public Debate on Metallic Hydrogen to Boost High Pressure Research
• Strong electron-phonon and band structure effects in the optical properties of high pressure metallic hydrogen
• Metallic hydrogen with a strong electron-phonon interaction at a pressure of 300-500 GPa

Cited by in corpus (10)

• Evidence for superconductivity above 260 K in lanthanum superhydride at megabar pressures
• Synthesis of clathrate cerium superhydride CeH9 below 100 GPa with atomic hydrogen sublattice
• A Perspective on Conventional High-Temperature Superconductors at High Pressure: Methods and Materials
• Magnetic measurements on micron-size samples under high pressure using designed NV centers
• Origin of High-Temperature Superconductivity in Compressed LaH${}_{10}$
• Beyond the Fröhlich Hamiltonian: Path integral treatment of large polarons in anharmonic solids
• Born effective charges and vibrational spectra in super and bad conducting metals
• Spectroscopic signatures of phonons in high pressure superconducting hydrides
• Optical properties of superconducting pressurized LaH${}_{10}$
• Infrared imaging of samples in ultra high pressure diamond anvil cells