Observation of Topological Edge States in Thermal Diffusion

Area of Science:

• Condensed matter physics
• Thermal transport phenomena
• Topological physics

Background:

• Topological band theory predicts edge states in nontrivial topological phases for wave systems.
• These phenomena are well-established for electromagnetic and acoustic waves.
• Diffusion systems, unlike wave systems, are anti-Hermitian with decay rates as eigenvalues.

Purpose of the Study:

• To extend the concept of band topology from wave systems to diffusion dynamics.
• To experimentally investigate topological phenomena in thermal diffusion.
• To explore the potential for defect-immune heat dissipation.

Main Methods:

• Experimental retrieval of the Hamiltonian for a thermal lattice.
• Direct probe of temperature diffusion dynamics.
• Observation and analysis of edge states within the bulk decay gap.

Main Results:

• Emergence of topological edge decays in a thermal lattice.
• Experimental confirmation of robust decay rates for these edge states.
• Demonstration that edge states are topologically protected against disorder.

Conclusions:

• This work establishes a thermal analogue of topological insulators.
• Topological edge states in diffusion dynamics exhibit robustness against disorder.
• The findings open avenues for developing defect-immune heat dissipation technologies.