Probing the Nodal Structure of Landau Level Wave Functions in Real Space

Area of Science:

• Condensed Matter Physics
• Surface Science
• Quantum Mechanics

Background:

• The study of electron behavior in low-dimensional systems is crucial for understanding quantum phenomena.
• Cesium (Cs) adsorption on indium antimonide (InSb) surfaces creates tunable electronic properties, specifically inversion layers.
• Landau levels describe the quantization of energy levels in a magnetic field, fundamental to 2D electron systems.

Purpose of the Study:

• To probe Landau level wave functions in the inversion layer of p-InSb(110) using scanning tunneling spectroscopy.
• To investigate the nodal structure of Landau level wave functions within smooth potential valleys.
• To visualize and characterize valley-confined drift states in real space.

Main Methods:

• Utilizing scanning tunneling spectroscopy (STS) at a high magnetic field (14 Tesla) to probe the electronic states.
• Employing Cesium (Cs) adsorption to create a p-InSb(110) inversion layer with specific properties.
• Applying a recursive Green function algorithm to model the experimental potential landscape and local density of states.

Main Results:

• Observed a double peak structure for the spin-polarized first Landau level, indicating nodal features.
• Identified a single peak structure for the zeroth Landau level per spin level.
• Real-space imaging revealed single rings for the zeroth Landau level and double rings for the first Landau level, corresponding to valley-confined drift states.

Conclusions:

• The observed nodal structures in Landau level wave functions are directly visualized and characterized.
• The experimental findings are consistent with theoretical models, including a recursive Green function algorithm and an analytic guiding center approach.
• This work demonstrates a generic method for probing wave function properties in confined electronic systems.