Large magneto-thermopower in MnGe with topological spin texture

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Electrodynamics

Background:

• Topological quantum states offer unique electrodynamics and electronic properties.
• Emergent electromagnetic fields arise from interactions between topological spin structures and electrons.
• Exploiting these phenomena for heat-electricity conversion remains largely unexplored.

Purpose of the Study:

• To investigate the potential of topological spin textures for thermoelectric applications.
• To explore the influence of magnetic fields on thermopower in materials hosting topological spin textures.
• To elucidate the mechanisms behind enhanced thermopower in such systems.

Main Methods:

• Synthesis and characterization of MnGe hosting topological spin textures.
• Quantitative investigation of electronic structures and transport properties.
• Magnetic field-dependent thermopower measurements, including high-field studies.

Main Results:

• An unusually enhanced thermopower was observed in MnGe upon application of a magnetic field.
• A large magneto-thermopower effect was linked to the energy-dependent charge-transport lifetime.
• Unconventional carrier scattering via emergent magnetic field dynamics was identified as a key factor.
• Residual magnetic fluctuations even in ferromagnetic regions contribute to the field-enhanced thermopower.

Conclusions:

• The study demonstrates a significant magneto-thermopower effect in MnGe with topological spin textures.
• Emergent magnetic fields and their dynamics play a crucial role in this enhanced thermoelectric response.
• This work opens avenues for developing thermoelectric functionalities in topological magnets.