Self-Induced Dirac Boundary State and Digitization in a Nonlinear Resonator Chain

Area of Science:

• Condensed matter physics
• Metamaterials science
• Nonlinear dynamics

Background:

• Low-energy excitations in condensed matter and metamaterials are often described by the Dirac equation.
• The Dirac mass term dictates band structure properties, influencing band gaps and linear dispersion.
• Domain walls separating regions with opposite Dirac masses host localized massless states (Jackiw-Rebbi modes).

Purpose of the Study:

• To experimentally demonstrate self-induced domain boundary formation for the Dirac mass in a 1D Dirac material.
• To investigate the role of material nonlinearity in creating these domain boundaries.
• To explore the resulting conductivity changes due to the self-induced boundary and its associated massless state.

Main Methods:

• Utilizing a dimerized magnetomechanical metamaterial for experimental control.
• Precisely controlling the magnitude and sign of local material nonlinearity.
• Precisely controlling the sign of the Dirac mass in different regions of the metamaterial.

Main Results:

• Nonlinearity was shown to induce a self-generated domain boundary for the Dirac mass.
• A massless bound state localized at this self-induced domain boundary was observed.
• The material exhibited a significant binary conductivity switch above an excitation threshold, mimicking a dopant site.

Conclusions:

• Nonlinear effects can engineer domain boundaries and localized states in 1D Dirac materials.
• Self-induced domain boundaries with massless states offer a novel mechanism for conductivity control.
• This phenomenon presents potential for advanced electronic devices and tunable metamaterials.