Quantum Critical Superfluid Flows and Anisotropic Domain Walls

TL;DR

This paper constructs anisotropic holographic domain walls representing quantum critical superfluid flows in string theory, revealing velocity-dependent existence and phase diagram similarities with superconductors.

Contribution

It introduces a new class of charged anisotropic AdS domain wall solutions modeling quantum critical superfluid flows with velocity constraints.

Findings

Domain walls exist only below a critical superfluid velocity.

Solutions flow to an IR AdS fixed point with emergent conformal invariance.

Phase diagrams resemble those of superconductors with imbalanced chemical potential.

Abstract

We construct charged anisotropic AdS domain walls as solutions of a consistent truncation of type IIB string theory. These are a one-parameter family of solutions that flow to an AdS fixed point in the IR, exhibiting emergent conformal invariance and quantum criticality. They represent the zero-temperature limit of the holographic superfluids at finite superfluid velocity constructed in arXiv:1010.5777. We show that these domain walls exist only for velocities less than a critical value, agreeing in detail with a conjecture made there. We also comment about the IR limits of flows with velocities higher than this critical value, and point out an intriguing similarity between the phase diagrams of holographic superfluid flows and those of ordinary superconductors with imbalanced chemical potential.