Programmable Kondo Effect Formed by Landau Levels

TL;DR

This paper demonstrates that graphene nanobubbles exhibit an intrinsic, strain-induced Kondo resonance associated with pseudo Landau levels, revealing a new tunable platform for studying correlated quantum phenomena.

Contribution

It uncovers a strain-engineered, flavor-frozen Kondo effect in graphene nanobubbles driven by pseudo Landau levels and introduces a new platform for simulating correlated phenomena.

Findings

Observation of intrinsic Kondo resonance in graphene nanobubbles

Strain-induced pseudo Landau levels enable tunable Kondo effects

Discovery of a flavor-frozen Kondo mechanism absent in conventional systems

Abstract

Nanobubbles wield significant influence over the electronic properties of 2D materials, showing diverse applications ranging from flexible devices to strain sensors. Here, we reveal that a strongly-correlated phenomenon, i.e., Kondo resonance, naturally takes place as an intrinsic property of graphene nanobubbles. The localized strain within the nanobubbles engenders pseudo magnetic fields, driving pseudo Landau levels with degenerate Landau orbits. Under the Coulomb repulsion, the Landau orbits form an effective $\mathrm{SU}(N)$ pseudospin coupled to the bath via exchange interaction. This results in a new flavor screening mechanism that drives an exotic flavor-frozen Kondo effect, which is absent in conventional Kondo systems. The resonance here also exhibits an unparalleled tunability via strain engineering, establishing a versatile new platform to simulate novel correlated phenomena based on pseudo Landau levels.