More Holographic Berezinskii-Kosterlitz-Thouless Transitions

TL;DR

This paper demonstrates two holographic models exhibiting quantum BKT phase transitions at nonzero density and magnetic field, including the first example in (3+1) dimensions, and analyzes their properties and spectra.

Contribution

It introduces two holographic systems with quantum BKT transitions, including the first in (3+1) dimensions, and develops holographic renormalization schemes for these models.

Findings

Quantum BKT transitions occur in ABJM with flavor and flavored little string theory.

Transition becomes second order at any nonzero temperature.

Constructed holographic renormalization for probe branes and analyzed meson spectra.

Abstract

We find two systems via holography that exhibit quantum Berezinskii-Kosterlitz-Thouless (BKT) phase transitions. The first is the ABJM theory with flavor and the second is a flavored (1,1) little string theory. In each case the transition occurs at nonzero density and magnetic field. The BKT transition in the little string theory is the first example of a quantum BKT transition in (3+1) dimensions. As in the "original" holographic BKT transition in the D3/D5 system, the exponential scaling is destroyed at any nonzero temperature and the transition becomes second order. Along the way we construct holographic renormalization for probe branes in the ABJM theory and propose a scheme for the little string theory. Finally, we obtain the embeddings and (half of) the meson spectrum in the ABJM theory with massive flavor.