Superfluid and Metamagnetic Phase Transitions in $\omega$-deformed Gauged Supergravity

TL;DR

This paper explores phase transitions, magnetization behavior, and superfluid instabilities in a specific class of $ ext{AdS}_4$ gauged supergravity models with $ ext{U}(1)$ gauge symmetry, revealing new vacua and complex phase structures.

Contribution

It introduces new $ ext{AdS}_4$ vacua, analyzes phase transitions including metamagnetic and superfluid phases, and examines the effects of $ ext{omega}$-deformation on these phenomena.

Findings

Identification of $ ext{omega}$-dependent $ ext{AdS}_4$ vacua

Discovery of a line of metamagnetic first-order phase transitions

Analysis of superfluid phase onset and its dependence on magnetic field sign

Abstract

We study non-supersymmetric truncations of $\omega$-deformed ${\cal N}=8$ gauged supergravity that retain a $U(1)$ gauge field and three scalars, of which two are neutral and one charged. We construct dyonic domain-wall and black hole solutions with AdS$_4$ boundary conditions when only one (neutral) scalar is non-vanishing, and examine their behavior as the magnetic field and temperature of the system are varied. In the infrared the domain-wall solutions approach either dyonic AdS$_2 \times \mathbb{R}^2$ or else Lifshitz-like, hyperscaling violating geometries. The scaling exponents of the latter are $z=3/2$ and $\theta = -2$, and are independent of the $\omega$-deformation. New $\omega$-dependent AdS$_4$ vacua are also identified. We find a rich structure for the magnetization of the system, including a line of metamagnetic first-order phase transitions when the magnetic field lies in a particular range. Such transitions arise generically in the $\omega$-deformed theories. Finally, we study the onset of a superfluid phase by allowing a fluctuation of the charged scalar field to condense, spontaneously breaking the abelian gauge symmetry. The mechanism by which the superconducting instability ceases to exist for strong magnetic fields is different depending on whether the field is positive or negative. Finally, such instabilities are expected to compete with spatially modulated phases.