Giant Magnetoresistance in Hubbard Chains

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics

Background:

• The one-dimensional Hubbard model is a fundamental system for studying strongly correlated electrons.
• Magnetoresistance, the change in electrical resistance of a material in a magnetic field, is a key phenomenon in condensed matter physics.

Purpose of the Study:

• To investigate the emergence of magnetoresistance in the one-dimensional Hubbard model with periodically distributed on-site interactions.
• To identify the minimal ingredients required for this phenomenon within the model.

Main Methods:

• Numerically unbiased methods were employed for accurate calculations.
• The Drude weight and single-particle density of states were computed.
• Twisted boundary condition averaging was used to mitigate finite-size effects.

Main Results:

• The one-dimensional Hubbard model inherently possesses the necessary components for magnetoresistance.
• Applying an external magnetic field significantly enhances charge transport.
• The study reproduces the established giant magnetoresistance picture without differentiating between itinerant and localized charges.

Conclusions:

• The one-dimensional Hubbard model serves as a minimal, yet complete, theoretical framework for understanding magnetoresistance.
• The indistinguishability of itinerant and localized charges simplifies the interpretation of magnetoresistance mechanisms.