Field theory for a deuteron quantum liquid

Abstract

Based on general symmetry principles we study an effective Lagrangian for a neutral system of condensed spin-1 deuteron nuclei and electrons, at greater-than-atomic but less-than-nuclear densities. We expect such matter to be present in thin layers within certain low-mass brown dwarfs. It may also be produced in future shock-wave-compression experiments as an effective fuel for laser-induced nuclear fusion. We find a background solution of the effective theory describing a net spin zero condensate of deuterons with their spins aligned and anti-aligned in a certain spontaneously emerged preferred direction. The spectrum of low energy collective excitations contains two spin-waves with linear dispersions -like in antiferromagnets -as well as gapped longitudinal and transverse modes related to the Meissner effect -like in superconductors. We show that counting of the Nambu-Goldstone modes of spontaneously broken internal and space-time symmetries obeys, in a nontrivial way, the rules of the Goldstone theorem for Lorentz non-invariant systems. We discuss thermodynamic properties of the condensate, and its potential manifestation in the low-mass brown dwarfs.

The phases of deuterium at extreme densities

“…Our effective theory, valid at distance scales larger than the deuteron radius is 'more microscopic' than the one in Ref. [1], valid at distances larger than l. As such, coefficients that are phenomenological in Ref. [1] can be computed in our theory.…”

“…[1], valid at distances larger than l. As such, coefficients that are phenomenological in Ref. [1] can be computed in our theory. In addition, we considered a more general symmetry breaking pattern (the ferromagnetic phase) than addressed in Ref.…”

“…[1] has a rich phase structure. To show this, we calculated the one-loop effective potential for the deuteron fields, and showed that to leading order, the theory enjoys an enhanced SU (3) global symmetry.…”

“…[1] is probably useful. Our effective theory, valid at distance scales larger than the deuteron radius is 'more microscopic' than the one in Ref.…”

“…First, this kind of matter is expected to exist in a layer inside brown dwarfs that are light enough not to ignite deuteron fusion [1]. Second, it may be created in terrestrial laboratories through shock compression [3,4], ex- * Electronic address: bedaque@physics.umd.edu † Electronic address: mbuchoff@physics.umd.edu ‡ Electronic address: alekseyc@physics.umd.edu periments using inertial confinement or other techniques [5,6].…”