Non-reciprocal topological solitons in active metamaterials

Area of Science:

• Nonlinear physics
• Metamaterials science
• Topological physics

Background:

• Topological solitons are robust nonlinear excitations found across diverse scientific fields.
• Existing driving methods accelerate solitons and antisolitons in opposite directions.
• A new local driving mechanism is needed to control soliton and antisoliton motion simultaneously.

Purpose of the Study:

• To introduce and demonstrate a novel non-reciprocal driving mechanism for topological solitons.
• To construct an active mechanical metamaterial capable of realizing this non-reciprocal driving.
• To explore the potential applications of non-reciprocal topological solitons in information transmission.

Main Methods:

• Construction of an active mechanical metamaterial with non-reciprocally coupled oscillators and a bistable potential.
• Observation and analysis of non-Hermitian skin waves induced by nonlinearity.
• Development of an active waveguide for transmitting and filtering unidirectional information.

Main Results:

• Demonstrated a local driving mechanism that accelerates both solitons and antisolitons in the same direction.
• Transformed typically unstable non-Hermitian skin waves into robust one-way (anti)solitons.
• Successfully harnessed non-reciprocal topological solitons for unidirectional information transmission.
• Illustrated the mechanism in metamaterials exhibiting broken 'supersymmetry', selectively driving antisolitons.

Conclusions:

• Non-reciprocity and topological solitons exhibit a subtle interplay, where solitons can generate their own driving force.
• Non-reciprocal solitons offer a new paradigm for controlling nonlinear excitations.
• This mechanism has potential applications in areas like robotic locomotion, quantum mechanics, optics, and soft matter.