Linear magnetoresistance in the low-field limit in density-wave materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Physics

Background:

• Magnetoresistance (MR) typically shows quadratic dependence on magnetic field and is insensitive to field direction.
• Linear MR can arise from quantum effects, topological band structures, or current path inhomogeneities.
• Existing linear MR mechanisms are often sensitive to low magnetic fields.

Purpose of the Study:

• To investigate metallic charge- and spin-density-wave systems exhibiting large positive linear MR.
• To understand the underlying physics of this robust linear MR phenomenon.
• To propose a semiclassical explanation applicable to materials with partially gapped Fermi surfaces.

Main Methods:

• Experimental exploration of metallic charge- and spin-density-wave systems.
• Measurement of magnetoresistance under varying magnetic field strengths and directions.
• Theoretical framing using a semiclassical approach.

Main Results:

• Identification of metallic charge- and spin-density-wave systems with extremely large positive linear MR.
• Demonstration that this linear MR effect is robust and observable at very low magnetic fields (tens of Oersted).
• Observation of the effect at low temperatures.

Conclusions:

• The studied density-wave systems present a unique platform for observing large, robust linear magnetoresistance.
• A semiclassical model provides a viable explanation for this phenomenon in materials with partially gapped Fermi surfaces.
• This work expands the understanding of non-conventional magnetoresistance mechanisms.