Holographic superfluid with excited states

TL;DR

This paper develops new holographic superfluid solutions with excited states, revealing how these states influence phase transitions, critical points, and conductivity features, notably suppressing the Cave of Winds phase structure.

Contribution

It introduces a family of excited state solutions in holographic superfluids, analyzing their effects on phase transitions and conductivity, which was not previously explored.

Findings

Higher excited states hinder scalar hair development.

Excited states promote first-order phase transitions over second-order.

Additional poles and delta functions appear in conductivity at low temperatures.

Abstract

We construct a novel family of solutions of the holographic superfluid model with the excited states in the probe limit. We observe that the higher excited state or larger superfluid velocity will make the scalar hair more difficult to be developed, and the higher excited state or smaller mass of the scalar field makes it easier for the emergence of translating point from the second-order transition to the first-order one. We note that the difference of the critical chemical potential between the consecutive states increases as the superfluid velocity increases. Interestingly, the "Cave of Winds" phase structure will disappear but the first-order phase transition occurs for the excited states, which is completely different from the holographic superfluid model with the ground state. This means that the excited state will hinder the appearance of the Cave of Winds. Moreover, we find that there exist additional poles in Im[$\sigma(\omega)$] and delta functions in Re[$\sigma(\omega)$] arising at low temperature for the excited states, and the higher excited state or larger superfluid velocity results in the larger deviation from the expected relation in the gap frequency.