arXiv subjects

David Galvez-Poblete

Publications and source records attributed to David Galvez-Poblete.

6 recordsLinked to original sources

arXiv2026

Moving Analogue Horizons in Stationary Ferroelectrics

We show that a traveling modulation of the polarization-gradient stiffness in a ferroelectric material induces an effective flow in its collective polarization dynamics. Within a controlled local approximation, small polarization fluctuations, or ferrons, obey a massive Klein-Gordon equation with flow. Unlike conventional analogue-gravity platforms, the effective flow originates from the modulation of the material parameters rather than from the physical transport of the medium. This mechanism enables mobile analogue horizons separating sub-ferronic and super-ferronic regions, the latter supporting negative-norm antiferron modes. Their coupling to positive-norm ferrons gives rise to superradiant-like amplification, while the effective mass gap can be tuned independently through an external electric field. Ferroelectric systems therefore provide a novel and experimentally controllable platform for analogue gravity with massive scalar excitations.

cond-mat.mes-hall↗

arXiv2026

Vacuum-selected timescales in driven Josephson systems

In this work, we demonstrate that the intrinsic timescale of a Josephson junction can be controlled through dynamical vacuum selection. By applying a Kapitza-like high-frequency drive to the system, the effective Josephson potential is reshaped, allowing for the stabilization of inphase or antiphase configuration. As a result, the Josephson plasma frequency, that is, the clock frequency of the junction, becomes a tunable property of the selected vacuum. Our findings establish a vacuum-controlled Josephson clock principle, in which the dynamical vacuum acts as an internal reference that fixes the operational timescale of Josephson oscillations, rather than this scale being imposed externally.

cond-mat.supr-con↗

arXiv2025

Antiferron Modes in Ferroelectric Materials

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.

cond-mat.mtrl-sci↗

arXiv2025

Electric-Field Control of Josephson Oscillations in Dipolar Bose-Einstein Condensates

We study the dynamic behavior of a Bose-Einstein condensate (BEC) with dipolar interactions when the influence of external electric fields affects the coherent tunneling properties. Here, we propose a tunable platform based on BECs where Josephson oscillations can be engineered and modulated through external electric fields. We develop a theoretical and numerical frame-work that reveals how electric fields affect intercondensate tunneling, phase dynamics, and collective excitations. By employing a coupled set of Gross-Pitaevskii equations with adiabatic elimination of excited states, we demonstrate field-induced tuning of Josephson frequencies and a transition from contact to dipole-dominated regimes. These findings corroborate theoretical predictions about the sensitivity of dipolar BECs to external fields and deepen our understanding of quantum coherence and tunneling in long-range interacting quantum systems.

cond-mat.quant-gas↗

arXiv2025

Magnetic Worms: Oscillatory Bimeron Pairing And Collective Transport In Patterned Stripes

Magnetic bimerons in a domain wall provide a practical route for current driven transport in patterned magnetic stripes. However, coupling between bimerons and pinning by defects complicate reliable motion. Here we show that a periodic array of edge defects both stabilizes transport of multiple bimerons and gives rise to a distinctive collective state, the magnetic worm. A single bimeron travels at constant speed; defects lower this speed while preserving an approximately linear relation between velocity $v$ and current density $J$. With two bimerons, the center of mass advances nearly uniformly while their separation exhibits a bounded oscillation whose frequency increases and amplitude decreases with current. For larger trains, these oscillations lose synchrony, producing segmented, worm like motion. The center of mass speed grows with current but decreases as the number of bimerons increases. Notably, eight bimerons cannot be sustained in a smooth stripe but can be stabilized by the periodic defects

cond-mat.mes-hall↗

arXiv2025

On the Electronic Contribution to Crystalline Diffraction Patterns

We introduce the electronic structure factor as a phase-sensitive contribution to diffraction that directly encodes the properties of the occupied-band wave functions. In the one-dimensional SSH model, $F_{\mathrm{cond}}$ is governed by the relative sublattice phase, which integrates to the Zak phase. This provides a clear diffraction-based criterion to distinguish trivial and topological regimes in the absence of any structural change. Beyond the SSH limit, the same Bloch-based construction naturally accounts for commensurate and incommensurate magnetic satellites in antiferromagnets, reproducing the additional peaks at $q=G\pm Q$ observed in NiO, MnO, chromium, and cuprates. These results demonstrate that diffraction can probe electronic topology and magnetic ordering on equal footing, opening a route to phase-sensitive structural characterization of correlated electron systems.

cond-mat.str-el↗