Magnetoconductivity in quasiperiodic graphene superlattices

Area of Science:

• Condensed matter physics
• Materials science
• Graphene physics

Background:

• Fibonacci superlattices exhibit quasiperiodic properties.
• Graphene's electronic properties are sensitive to structural modifications and magnetic fields.

Purpose of the Study:

• Investigate magnetoconductivity in Fibonacci graphene superlattices.
• Analyze the influence of perpendicular magnetic fields on conductivity.
• Explore the absence of Weiss oscillations and the nature of observed oscillations.

Main Methods:

• Theoretical investigation of magnetoconductivity.
• Analysis of diffusive and dc Hall conductivity.
• Examination of Fermi velocity renormalization and self-similarity.

Main Results:

• Magnetoconductivity exhibits Shubnikov-de Haas oscillations, not Weiss oscillations, due to incommensurate periods.
• Quasiperiodicity renormalizes graphene's Fermi velocity.
• Absence of half-integer quantum Hall effect observed; dc Hall conductivity shows unexpected plateaux.
• Self-similarity in conductivity is found for specific magnetic field ratios related to the golden mean.

Conclusions:

• Fibonacci graphene superlattices display unique magnetotransport phenomena.
• The structure's quasiperiodicity fundamentally alters electronic behavior compared to periodic superlattices.
• The findings challenge conventional understanding of quantum Hall effects in such systems.