New Frontiers in Superconductivity: Superhydrides at High Pressures
Invited
Abstract
One of the long-standing challenges in experimental physics is the observation of room-
temperature superconductivity (RTSC). More than a century of rigorous research has led
physicists to believe that the highest T c that can be achieved is 40 K for conventional
superconductors. However, the discovery of superconductivity in hydrogen sulfide (H 2 S) at 203
K changed the notion of what might be possible for phonon–mediated superconductors. As H 2 S
readily mixes with hydrogen to form guest-host structures at lower pressures, the comparable
size of methane (CH 4 ) to H 2 S should allow molecular exchange within a large assemblage of van
der Waals solids that are (highly) hydrogen-rich with H 2 inclusions that are then the building
blocks for novel superconducting compounds at extreme conditions. Here, we report
superconductivity in a photochemically transformed carbonaceous sulfur hydride system with a
maximum superconducting transition temperature of 287.7 ± 1.2 K (~15° C) achieved at 267 ±
10 GPa. Superconductivity is established by the observation of zero resistance, magnetic
susceptibility of up to 190 GPa, and reduction of the transition temperature under an external
magnetic field of up to 9 T, with an upper critical magnetic field of about 62 T according to the
Ginzburg–Landau model at zero temperature. The Raman spectroscopy is used to probe the
chemical and structural transformations before metallization. The discovery achieves the more
than a century long quest to find room temperature superconductivity, a phenomenon that was
first observed by Kamerlingh Onnes in 1911.
temperature superconductivity (RTSC). More than a century of rigorous research has led
physicists to believe that the highest T c that can be achieved is 40 K for conventional
superconductors. However, the discovery of superconductivity in hydrogen sulfide (H 2 S) at 203
K changed the notion of what might be possible for phonon–mediated superconductors. As H 2 S
readily mixes with hydrogen to form guest-host structures at lower pressures, the comparable
size of methane (CH 4 ) to H 2 S should allow molecular exchange within a large assemblage of van
der Waals solids that are (highly) hydrogen-rich with H 2 inclusions that are then the building
blocks for novel superconducting compounds at extreme conditions. Here, we report
superconductivity in a photochemically transformed carbonaceous sulfur hydride system with a
maximum superconducting transition temperature of 287.7 ± 1.2 K (~15° C) achieved at 267 ±
10 GPa. Superconductivity is established by the observation of zero resistance, magnetic
susceptibility of up to 190 GPa, and reduction of the transition temperature under an external
magnetic field of up to 9 T, with an upper critical magnetic field of about 62 T according to the
Ginzburg–Landau model at zero temperature. The Raman spectroscopy is used to probe the
chemical and structural transformations before metallization. The discovery achieves the more
than a century long quest to find room temperature superconductivity, a phenomenon that was
first observed by Kamerlingh Onnes in 1911.
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Presenters
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Ranga P Dias
University of Rochester, Department of Physics and Astronomy, University of Rochester, Physics and Astronomy, University of Rochester, University of Rochester, Assistant Professor of Mechanical Engineering and Physics
Authors
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Ranga P Dias
University of Rochester, Department of Physics and Astronomy, University of Rochester, Physics and Astronomy, University of Rochester, University of Rochester, Assistant Professor of Mechanical Engineering and Physics