Competing orders in M-theory: superfluids, stripes and metamagnetism

TL;DR

This paper explores the phase structure of a class of 3D conformal field theories via their gravity duals, revealing superfluid, striped, and metamagnetic phases, with detailed analysis of instabilities and IR behaviors.

Contribution

It constructs and analyzes black hole solutions in supergravity duals, identifying phase transitions and instabilities under magnetic fields, including a novel hyperscaling violating IR phase.

Findings

Superfluid instability disappears at high magnetic fields.

Stripe instability persists even when superfluidity is suppressed.

First-order metamagnetic phase transition occurs at large magnetic fields.

Abstract

We analyse the infinite class of d=3 CFTs dual to skew-whiffed AdS_4 X SE_7 solutions of D=11 supergravity at finite temperature and charge density and in the presence of a magnetic field. We construct black hole solutions corresponding to the unbroken phase, and at zero temperature some of these become dyonic domain walls of an Einstein-Maxwell-pseudo-scalar theory interpolating between AdS_4 in the UV and new families of dyonic AdS_2 X R^2 solutions in the IR. The black holes exhibit both diamagnetic and paramagnetic behaviour. We analyse superfluid and striped instabilities and show that for large enough values of the magnetic field the superfluid instability disappears while the striped instability remains. For larger values of the magnetic field there is also a first-order metamagnetic phase transition and at zero temperature these black hole solutions exhibit hyperscaling violation in the IR with dynamical exponent z=3/2 and \theta=-2.