Novel Hydrogen-rich Materials at High Pressures: Possible Route to Room Temperature Superconductivity

University Of Rochester, Rochester NY

Investigators

Abstract

Non-technical Abstract: Superconductors, which conduct electricity without resistance, are among the most fascinating materials in condensed matter physics. Achieving a state of superconductivity at room temperature or near room temperature will revolutionize our energy production and transportation system and will enhance economic growth and quality of life. Pressure has been proven to be the most versatile tuning parameter in making novel materials with exotic properties such as superconductivity. Solid metallic hydrogen, the high pressure phase of hydrogen, is predicted to have room temperature superconductivity. However, it requires extreme pressure. Hydrogen-rich materials, mimicking the elusive solid metallic phase of hydrogen, may lead to high-Tc superconductivity at much lower pressures. The primary goal of this project is to synthesize novel hydrogen-rich superconducting materials at high pressure temperature conditions and explore their possible room temperature superconductivity. Progress on this project can provide greater clarity regarding superconducting mechanisms. In turn, it may allow us to obtain insight into designing new superconducting materials in large quantities at ambient pressure. Through a comprehensive outreach approach, the principal investigator will recruit and mentor high school students to provide experiences to foster their scientific inquiry and communication skills. A goal of the outreach is to reach students who are underrepresented in the areas of science, technology, engineering, and mathematics. The principal investigator works with the University of Rochester's McNair program, whose mission is to increase the numbers of low-income, first generation, and underrepresented minority undergraduates who pursue PhD degrees. Technical Abstract: Superconductivity has been one of the most arcane quantum phases in condensed matter physics. Solid metallic hydrogen is theorized to have the high Debye temperature and strong electron-phonon coupling that are necessary for high-Tc phonon-mediated superconductivity. However, it requires extreme pressure. As an alternative, hydrogen-rich materials, mimicking the elusive solid metallic phase of hydrogen, can be metalized at much lower pressures, providing large hydrogen-derived electronic density of states at the Fermi level and large modifications of the electronic structure in response to the motion of hydrogen atoms (electron-phonon coupling). The primary goal of this research is to synthesize novel hydrogen rich superconducting materials that are either known or likely to exhibit high Tc superconductivity. State-of-the-art high pressure and high temperature techniques, laser spectroscopy, and low temperature techniques in conjunction with novel transport measurements are used to synthesize and probe high temperature superconductivity. Success on this project elucidates greater clarity in superconducting mechanisms. In turn, it may allow the research team to obtain insight into designing new superconducting materials in large quantities at ambient pressure. The project also provides graduate students hands-on experience with cutting-edge nano-fabrication technologies and large user facilities, such as synchrotron and neutron facilities. In addition, the project offers summer internships to local high school students, and the principal investigator works with the University of Rochester's McNair program, whose mission is to increase the numbers of low-income, first generation, and underrepresented minority undergraduates who pursue PhD degrees, to recruit and mentor students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.