Observability of a projected new state of matter: a metallic superfluid

TL;DR

This paper discusses the theoretical possibility of observing a new metallic superfluid state in liquid metallic hydrogen and proposes four experimental methods to detect it.

Contribution

It introduces the concept of a metallic superfluid in liquid metallic hydrogen and suggests four experimental probes for its observation.

Findings

Proposed four experimental probes for detecting metallic superfluid.

Discussed the conditions under which liquid metallic hydrogen could exhibit this state.

Analyzed the feasibility of observing the metallic superfluid at high pressures.

Abstract

Dissipationless quantum states, such as superconductivity and superfluidity, have attracted interest for almost a century. A variety of systems exhibit these macroscopic quantum phenomena, ranging from superconducting electrons in metals to superfluid liquids, atomic vapours, and even large nuclei. It was recently suggested that liquid metallic hydrogen could form two new unusual dissipationless quantum states, namely the metallic superfluid and the superconducting superfluid. Liquid metallic hydrogen is projected to occur only at an extremely high pressure of about 400 GPa, while pressures on hydrogen of 320 GPa having already been reported. The issue to be adressed is if this state could be experimentally observable in principle. We propose four experimental probes for detecting it.