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arXiv · 1708.08306

Pinning of longitudinal phonons in holographic spontaneous helices

Tomas Andrade·Matteo Baggioli·Alexander Krikun·Napat Poovuttikul
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Abstract

We consider the spontaneous breaking of translational symmetry and identify the associated Goldstone mode -- a longitudinal phonon -- in a holographic model with Bianchi VII helical symmetry. For the first time in holography, we observe the pinning of this mode after introducing a source for explicit breaking compatible with the helical symmetry of our setup. We study the dispersion relation of the resulting pseudo-Goldstone mode, uncovering how its speed and mass gap depend on the amplitude of the source and temperature. In addition, we extract the optical conductivity as a function of frequency, which reveals a metal-insulator transition as a consequence of the pinning.

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Tomas Andrade, Matteo Baggioli, Alexander Krikun, Napat Poovuttikul. 2018-01-21. Pinning of longitudinal phonons in holographic spontaneous helices. https://doi.org/10.1007/jhep02(2018)085

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