Holographic quantum criticality from multi-trace deformations

TL;DR

This paper investigates how multi-trace deformations in gauge-gravity duality can induce spontaneous symmetry breaking, create holographic superconductors, and lead to new quantum critical points with unique critical exponents.

Contribution

It introduces multi-trace deformations as a new control parameter to realize quantum criticality and holographic superconductivity in gauge-gravity duality frameworks.

Findings

Multi-trace deformations enable spontaneous symmetry breaking.

They can tune the critical temperature to zero, creating new quantum critical points.

Critical exponents depend on operator dimensions at the critical point.

Abstract

We explore the consequences of multi-trace deformations in applications of gauge-gravity duality to condensed matter physics. We find that they introduce a powerful new "knob" that can implement spontaneous symmetry breaking, and can be used to construct a new type of holographic superconductor. This knob can be tuned to drive the critical temperature to zero, leading to a new quantum critical point. We calculate nontrivial critical exponents, and show that fluctuations of the order parameter are `locally' quantum critical in the disordered phase. Most notably the dynamical critical exponent is determined by the dimension of an operator at the critical point. We argue that the results are robust against quantum corrections and discuss various generalizations.