학술논문
Observation of Conventional Near Room Temperature Superconductivity in Carbonaceous Sulfur Hydride
Document Type
Working Paper
Author
Pasan, Hiranya; Snider, Elliot; Munasinghe, Sasanka; Dissanayake, Sachith E.; Salke, Nilesh P.; Ahart, Muhtar; Khalvashi-Sutter, Nugzari; Dasenbrock-Gammon, Nathan; McBride, Raymond; Smith, G. Alexander; Mostafaeipour, Faraz; Smith, Dean; Cortés, Sergio Villa; Xiao, Yuming; Kenney-Benson, Curtis; Park, Changyong; Prakapenka, Vitali; Chariton, Stella; Lawler, Keith V.; Somayazulu, Maddury; Liu, Zhenxian; Hemley, Russell J.; Salamat, Ashkan; Dias, Ranga P.
Source
Subject
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Abstract
The phenomenon of high temperature superconductivity, approaching room temperature, has been realized in a number of hydrogen-dominant alloy systems under high pressure conditions1-12. A significant discovery in reaching room temperature superconductivity is the photo-induced reaction of sulfur, hydrogen, and carbon that initially forms of van der Waals solids at sub-megabar pressures. Carbonaceous sulfur hydride has been demonstrated to be tunable with respect to carbon content, leading to different superconducting final states with different structural symmetries. A modulated AC susceptibility technique adapted for a diamond anvil cell confirms a Tc of 260 kelvin at 133 GPa in carbonaceous sulfur hydride. Furthermore, direct synchrotron infrared reflectivity measurements on the same sample under the same conditions reveal a superconducting gap of ~85 meV at 100 K in close agreement to the expected value from Bardeen-Cooper-Schrieffer (BCS) theory13-18. Additionally, x-ray diffraction in tandem with AC magnetic susceptibility measurements above and below the superconducting transition temperature, and as a function of pressure at 107-133 GPa, reveal the Pnma structure of the material is responsible for the close to room-temperature superconductivity at these pressures.