Ground-state properties and elementary excitations of superfluid spin-aligned atomic H are studied using methods adapted from the theory of liquid $^{4}\mathrm{He}$ . The ground state is a $k=0$ condensate of the $|\ensuremath{\downarrow} (\mathrm{electron}), \ensuremath{\uparrow} (\mathrm{proton})〉$ hyperfine state with a small admixture of $|\ensuremath{\uparrow}\ensuremath{\downarrow}〉$ due to the hyperfine interaction. Excitations can also be labeled approximately by their hyperfine states. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ excitations are phononlike. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ are free-particle-like with energy gaps, and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ excitations resemble spin waves.Ground-state properties and elementary excitations of superfluid spin-aligned atomic H are studied using methods adapted from the theory of liquid $^{4}\mathrm{He}$. The ground state is a $k=0$ condensate of the $|\ensuremath{\downarrow} (\mathrm{electron}), \ensuremath{\uparrow} (\mathrm{proton})〉$ hyperfine state with a small admixture of $|\ensuremath{\uparrow}\ensuremath{\downarrow}〉$ due to the hyperfine interaction. Excitations can also be labeled approximately by their hyperfine states. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ excitations are phononlike. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ are free-particle-like with energy gaps, and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ excitations resemble spin waves.

Physical Review LettersAug 8, 197724 citations

Collisional quenching of metastable hydrogen by ground-state hydrogen atoms

M. Raymond Flannery

PhysicaMay 1, 19715 citations

Chapter 3: Spin-Polarized Atomic Hydrogen

Isaac F. Silvera, Jook T. M. Walraven

Progress in low temperature physicsJan 1, 198675 citations

Ground-state properties and elementary excitations of superfluid spin-aligned atomic H are studied using methods adapted from the theory of liquid

^{4}\mathrm{He}

. The ground state is a

k=0

condensate of the $|\ensuremath{\downarrow} (\mathrm{electron}), \ensuremath{\uparrow} (\mathrm{proton})〉$ hyperfine state with a small admixture of $|\ensuremath{\uparrow}\ensuremath{\downarrow}〉$ due to the hyperfine interaction. Excitations can also be labeled approximately by their hyperfine states. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ excitations are phononlike. ${\ensuremath{\phi}}_{\ensuremath{\downarrow}\ensuremath{\uparrow}}(k)$ and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ are free-particle-like with energy gaps, and ${\ensuremath{\phi}}_{\ensuremath{\uparrow}\ensuremath{\downarrow}}(k)$ excitations resemble spin waves.