Antiferron Modes in Ferroelectric Materials

Abstract

We introduce the concept of antiferron modes in ferroelectric materials as dynamically stabilized collective excitations over inverted polarization states that decrease the system energy. While ferrons represent quantized oscillations around the stable polarization minimum, antiferrons require dynamic stabilization via high-frequency driving. Using a generalized Landau-Ginzburg-Devonshire framework, we derive the effective curvature corrections from external driving, demonstrate the conditions for stabilizing metastable wells, and present the quantized Hamiltonian. Antiferrons could be a promising candidate for developing electrical sensing devices, offering tunable, dynamically controllable excitations with high sensitivity to external electric fields.

Figures (3)

• Figure 1: Free energy of ferroelectric system. $P_o$ and $-P_o$ corresponds to the stable minima of the system and $P_u$ denotes the unstable configuration at the local maximum. The inset show the dynamical stabilization of the unstable configuration with $J_p = \varepsilon cos(\Omega t) \delta P$, with $\varepsilon = 3.45\times10^{10} Jm/C^2$ and $\Omega = 10 \omega_o$.
• Figure 2: Antiferron modes: stabilization diagram as a function of driving amplitude $\varepsilon$ and frequency $\Omega$. The diagram displays three regions. (I) corresponds to driving parameters insufficient to stabilize the inverted state, with $a_{\text{eff}}<0$. (II) denotes the regime where dynamic stabilization occurs and antiferron modes emerge. (III) represents the range where the driving fully stabilizes the previously inverted state, with $a_{\text{eff}}>0$, but only supports ferronic excitations.
• Figure 3: Dispersion relations for collective excitations in ferroelectric system. The red curve denotes antiferron modes, and the green curve represents ferron modes around the unstable point. The blue curve represents the typical ferron modes around the global minima. The dash line represents the $k_c$ that defines if the excitations corresponds to ferron or antiferron modes.