Producing metallic hydrogen has been a great challenge in condensed matter physics. Metallic hydr... more Producing metallic hydrogen has been a great challenge in condensed matter physics. Metallic hydrogen may be a room-temperature superconductor and metastable when the pressure is released and could have an important impact on energy and rocketry. We have studied solid molecular hydrogen under pressure at low temperatures. At a pressure of 495 gigapascals, hydrogen becomes metallic, with reflectivity as high as 0.91. We fit the reflectance using a Drude free-electron model to determine the plasma frequency of 32.5 ± 2.1 electron volts at a temperature of 5.5 kelvin, with a corresponding electron carrier density of 7.7 ± 1.1 × 10(23) particles per cubic centimeter, which is consistent with theoretical estimates of the atomic density. The properties are those of an atomic metal. We have produced the Wigner-Huntington dissociative transition to atomic metallic hydrogen in the laboratory.
For over eighty years, scientists have been trying to produce lab-made metallic hydrogen, the hol... more For over eighty years, scientists have been trying to produce lab-made metallic hydrogen, the holy grail of alternative fuels. In that process, diamond anvils must withstand pressures greater than those at the center of the earth—no mean feat. Recent research may have finally achieved hydrogen’s metallic state. All that remains is for another lab to reproduce the results.
Publisher Summary This chapter reviews the properties of new quantum gases and properties of spin... more Publisher Summary This chapter reviews the properties of new quantum gases and properties of spin-polarized tritium. The hydrogen (H 2 ) atom with its single electron and proton, bearing a spinoff is the simplest and most abundant atom in the universe. The atomic species in a discharge is short lived and is recombined to form H 2 . The hydrogen maser, which operates on the zero-field hyperfine transitions of the hydrogen atom, has become the most stable time and frequency source in existence. The chapter discusses the properties of new quantum gases and some of the properties of spin-polarized tritium (Ti). These new quantum gases promise to have many new and exciting properties in the low-temperature, high-density regime of quantum degeneracy. The chapter also describes the theory of decay. Magnetic properties of the many-body gas concentrates on many-body phenomena on surfaces or in two-dimension. In the condensed state, hydrogen and its isotope deuterium provide physics with the two fundamental many-body quantum systems of nature, boson- and fermion-fluids. Because of its very light mass and weak interactions, a many-particle system of electron spin-polarized hydrogen is predicted to have the unique property that it will remain in the gaseous state at the absolute zero of temperature.
We describe a technique for producing a high-flux beam of atomic hydrogen with a velocity distrib... more We describe a technique for producing a high-flux beam of atomic hydrogen with a velocity distribution corresponding to liquid-helium temperatures. We have studied how a gas of hydrogen atoms (H) may be cooled to low temperatures through interaction with cold walls. The gas was analyzed by forming an atomic beam. We obtained fluxes φH≃2.4×1016 atoms/s at T≃8 K, which corresponds to an increase in flux of low-velocity atoms by a factor of 20 over that of the same source operated at room temperature. The degree of dissociation and the translational temperature of the gas were determined using a quadrupole mass spectrometer and time-of-flight techniques. A beam modulation technique advantageous for such a system is discussed and analyzed. General design considerations for the transport and cooling of H are presented and illustrated with examples. The methods of data analyses are discussed in detail.
Atomic hydrogen (H) has recently been created in a long-lived state referred to as spin-polarized... more Atomic hydrogen (H) has recently been created in a long-lived state referred to as spin-polarized atomic hydrogen (H↓). A moderate density gas (n≃1017 atoms/ cc) has been produced at temperatures T≃400 mK. H↓ is predicted to be the only atomic substance that remains gaseous to T = 0 K; current experiments are consistent with this picture. Since the H↓ atoms behave as composite bosons the gas is expected to have a Bose-Einstein condensation (BEC) and related superfluidity at a sufficiently high density or low temperature. H↓ is expected to display spectacular static and dynamic properties. Since the gas is polarized, the dominant electronic magnetization, M⃗e, is proportional to the atomic density. In an inhomogeneous magnetic field M⃗e will also be highly inhomogeneous. BEC will be spatially localized and the static M⃗e should be an identifying feature of this state. The low-lying excitation spectrum should not only feature electronic and nuclear spin-transitions, but should also have magnetic translational modes of the gas. The experimental technique for stabilization of H↓ as well as many of the predicted magnetic properties are discussed.
Producing metallic hydrogen has been a great challenge in condensed matter physics. Metallic hydr... more Producing metallic hydrogen has been a great challenge in condensed matter physics. Metallic hydrogen may be a room-temperature superconductor and metastable when the pressure is released and could have an important impact on energy and rocketry. We have studied solid molecular hydrogen under pressure at low temperatures. At a pressure of 495 gigapascals, hydrogen becomes metallic, with reflectivity as high as 0.91. We fit the reflectance using a Drude free-electron model to determine the plasma frequency of 32.5 ± 2.1 electron volts at a temperature of 5.5 kelvin, with a corresponding electron carrier density of 7.7 ± 1.1 × 10(23) particles per cubic centimeter, which is consistent with theoretical estimates of the atomic density. The properties are those of an atomic metal. We have produced the Wigner-Huntington dissociative transition to atomic metallic hydrogen in the laboratory.
For over eighty years, scientists have been trying to produce lab-made metallic hydrogen, the hol... more For over eighty years, scientists have been trying to produce lab-made metallic hydrogen, the holy grail of alternative fuels. In that process, diamond anvils must withstand pressures greater than those at the center of the earth—no mean feat. Recent research may have finally achieved hydrogen’s metallic state. All that remains is for another lab to reproduce the results.
Publisher Summary This chapter reviews the properties of new quantum gases and properties of spin... more Publisher Summary This chapter reviews the properties of new quantum gases and properties of spin-polarized tritium. The hydrogen (H 2 ) atom with its single electron and proton, bearing a spinoff is the simplest and most abundant atom in the universe. The atomic species in a discharge is short lived and is recombined to form H 2 . The hydrogen maser, which operates on the zero-field hyperfine transitions of the hydrogen atom, has become the most stable time and frequency source in existence. The chapter discusses the properties of new quantum gases and some of the properties of spin-polarized tritium (Ti). These new quantum gases promise to have many new and exciting properties in the low-temperature, high-density regime of quantum degeneracy. The chapter also describes the theory of decay. Magnetic properties of the many-body gas concentrates on many-body phenomena on surfaces or in two-dimension. In the condensed state, hydrogen and its isotope deuterium provide physics with the two fundamental many-body quantum systems of nature, boson- and fermion-fluids. Because of its very light mass and weak interactions, a many-particle system of electron spin-polarized hydrogen is predicted to have the unique property that it will remain in the gaseous state at the absolute zero of temperature.
We describe a technique for producing a high-flux beam of atomic hydrogen with a velocity distrib... more We describe a technique for producing a high-flux beam of atomic hydrogen with a velocity distribution corresponding to liquid-helium temperatures. We have studied how a gas of hydrogen atoms (H) may be cooled to low temperatures through interaction with cold walls. The gas was analyzed by forming an atomic beam. We obtained fluxes φH≃2.4×1016 atoms/s at T≃8 K, which corresponds to an increase in flux of low-velocity atoms by a factor of 20 over that of the same source operated at room temperature. The degree of dissociation and the translational temperature of the gas were determined using a quadrupole mass spectrometer and time-of-flight techniques. A beam modulation technique advantageous for such a system is discussed and analyzed. General design considerations for the transport and cooling of H are presented and illustrated with examples. The methods of data analyses are discussed in detail.
Atomic hydrogen (H) has recently been created in a long-lived state referred to as spin-polarized... more Atomic hydrogen (H) has recently been created in a long-lived state referred to as spin-polarized atomic hydrogen (H↓). A moderate density gas (n≃1017 atoms/ cc) has been produced at temperatures T≃400 mK. H↓ is predicted to be the only atomic substance that remains gaseous to T = 0 K; current experiments are consistent with this picture. Since the H↓ atoms behave as composite bosons the gas is expected to have a Bose-Einstein condensation (BEC) and related superfluidity at a sufficiently high density or low temperature. H↓ is expected to display spectacular static and dynamic properties. Since the gas is polarized, the dominant electronic magnetization, M⃗e, is proportional to the atomic density. In an inhomogeneous magnetic field M⃗e will also be highly inhomogeneous. BEC will be spatially localized and the static M⃗e should be an identifying feature of this state. The low-lying excitation spectrum should not only feature electronic and nuclear spin-transitions, but should also have magnetic translational modes of the gas. The experimental technique for stabilization of H↓ as well as many of the predicted magnetic properties are discussed.
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