Work

Sign-engineered interactions enable dynamic frustration and topology in a passive elastic lattice

Year: 2026

Type: article

Abstract: The sign and strength of interactions between coupled elements dictate collective behavior across diverse physical systems. While active modulation can engineer these interactions, passive systems typically rely on fixed structures that require a change in lattice connectivity or global symmetry to reverse interaction signs. Here we demonstrate that local anisotropy enables continuous Hamiltonian sign engineering in central-force elastic lattices. Rotating the internal anisotropic confinement projects interactions onto local degrees of freedom, decomposing the dynamics into spectrally separated 1D Hamiltonians. This allows the effective couplings to be tuned from positive to negative via rotation alone, without altering the underlying force law or lattice connectivity. Implemented in a zigzag magnetoelastic lattice, this mechanism enables the simultaneous emergence of frequency-selective frustration and topological band inversion. Our results establish local anisotropy as a general tool for Hamiltonian engineering, providing a classical analogue to phonon-mediated interaction design in quantum many-body platforms.

Source: Communications Physics

DOI: 10.1038/s42005-026-02799-x

Authors: Taehwa Lee, Ziqi Yu, Xiaoshi Su, Hyung-Suk Kwon, Chiara Daraio

Institutions: Toyota Motor North America (United States), Toyota Motor North America Research & Development (United States), California Institute of Technology

Language: English

Topic: Acoustic Wave Phenomena Research

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,990

OpenAlex ID: W7172306002