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Disorder-induced magnetoresistance in a two-dimensional electron system
Jinglei Ping1, Indra Yudhistira2, Navneeth Ramakrishnan2
1Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111, USA and School of Physics, Monash University, Victoria 3800, Australia.
Physical Review Letters
|August 9, 2014
Summary
Disorder creates uneven electron density, causing magnetoresistance (MR) in 2D systems. This MR effect, observed in graphene, is a universal phenomenon linked to carrier density fluctuations.
Area of Science:
- Condensed matter physics
- Materials science
- Two-dimensional electron systems
Background:
- Carrier density inhomogeneity is a known factor in electronic properties.
- Magnetoresistance (MR) in two-dimensional electron systems (2DES) is complex.
- Understanding disorder effects is crucial for novel electronic materials.
Purpose of the Study:
- To predict and demonstrate the link between disorder-induced carrier inhomogeneity and MR.
- To investigate the MR behavior in graphene.
- To develop a theoretical model explaining the observed MR.
Main Methods:
- Experimental measurements of magnetoresistance in graphene.
- Theoretical modeling using effective medium calculations.
- Analysis of the relationship between carrier density and its fluctuations.
Main Results:
- Demonstrated that carrier density inhomogeneity causes MR in 2DES.
- Observed a quadratic MR in graphene persisting away from the charge neutrality point.
- Found MR to be a universal function of carrier density to fluctuation ratio, agreeing with experimental data.
Conclusions:
- Disorder-induced carrier density inhomogeneity is a primary cause of MR in 2DES.
- The MR phenomenon is generic and applicable to other materials with similar inhomogeneity.
- This finding offers new insights into electron transport in disordered systems.
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