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Updated: Sep 20, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Dynamical Breaking of Inversion Symmetry, Strong Second Harmonic Generation, and Nonequilibrium Ferroelectricity with
1Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany.
Abstract:
We show how crystalline inversion symmetry can be dynamically broken by optical phonons with generic, hardening Kerr-like nonlinearities. The symmetry-broken state is reached through a parametric instability that can be accessed by driving close to half the phonon frequency. The system then settles to a steady state with inversion symmetry breaking phonon trajectories and strong second harmonic generation. The time averaged positions of the atoms are displaced relative to equilibrium, resulting in a ferroelectric rectification of the driving signal. For circularly polarized phonons, complex Lissajous-like trajectories, resulting in structured magnetic fields within a unit cell, can be achieved.
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