Dipole-induced transition in 3 dimensions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Soft Matter Physics

Background:

• Topological phase transitions, like the Kosterlitz-Thouless and Hexatic transitions, are well-established phenomena driven by dipoles (vortices, dislocations) but are confined to two dimensions.
• Understanding transitions in amorphous solids is crucial for predicting material behavior under stress.

Purpose of the Study:

• To investigate a novel dipole-induced transition in the 3D mechanical response of amorphous solids to applied strain.
• To identify and characterize an intermediate phase between normal elastic response and fluid states in amorphous solids.
• To elucidate the role of nonaffine quadrupolar events and symmetry breaking in this 3D transition.

Main Methods:

• Analysis of the mechanical response of athermal amorphous solids under varying pressure (strain).
• Characterization of the displacement field to identify nonaffine quadrupolar events.
• Examination of angular correlations and their correlation lengths to determine critical scaling exponents.

Main Results:

• Identification of a genuine dipole-induced transition in 3D amorphous solids, distinct from 2D topological transitions.
• Discovery of an intermediate phase characterized by plasticity and nonaffine quadrupolar events, occurring between high-pressure elastic and zero-pressure fluid states.
• Observation of symmetry breaking (translational and chiral) due to screened elasticity, with diverging correlation lengths at the transition.

Conclusions:

• The study presents a new class of dipole-induced transitions in 3D amorphous solids, extending the concept beyond 2D topological systems.
• The identified intermediate phase exhibits unique mechanical properties driven by quadrupolar events and symmetry breaking.
• The findings provide critical insights into the fundamental physics of amorphous solids and their response to mechanical stress.