Unusual Hall effect anomaly in MnSi under pressure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• The helical magnet manganese silicon (MnSi) exhibits complex magnetic properties.
• Understanding exotic electronic transport phenomena in magnetic materials is crucial.

Purpose of the Study:

• To investigate the unusual Hall current observed in MnSi under applied pressure.
• To elucidate the origin of the distinctive Hall conductivity profile.

Main Methods:

• Experimental observation of Hall current in MnSi.
• Application of high pressure (6-12 kbars).
• Analysis of Hall conductivity field profiles.

Main Results:

• A highly unusual Hall current was observed in MnSi at 6-12 kbars.
• The Hall conductivity showed a distinctive stepwise field profile.
• This phenomenon is attributed to an effective real-space magnetic field from chiral spin textures.

Conclusions:

• The observed Hall anomaly in MnSi is likely caused by chiral spin textures.
• This chiral spin mechanism may be a precursor to the partial-order state observed at higher pressures (>14.6 kbar).