83Bi BISMUTHA SMALL EXPLORATION OF MATTERBehind the model ↗
INTERACTIVE SCIENCE · MODEL EXPLORATION

What if electrons
had a neighborhood?

Choose a material. Tune the energy. Discover where electronic
states spread out—and where they gather.

YOUR ELECTRON NEIGHBORHOOD

A smooth neighborhood

Regular atoms create a repeating environment.
The bright dots illustrate a relatively spread-out state.

Conceptual animation
Bright glow = more local state weight
PROBABILITY, MADE VISIBLE
Ordered bismuthIdeal superlatticeDisordered alloy
01

The energy dial

TUNE IN

Think of energy as a radio frequency. Peaks indicate where more electronic states are available to tune into.

0.00 model units
−2.300 · Fermi level+2.30
Available states at selected energystates / basis state / model energy
0.00

Recomputed from the repository’s 48-site Hamiltonian. Gaussian broadening σ = 0.065; normalized per Hamiltonian basis state.

02

Spread out or clustered?

EXPLORE

Each point represents a near-Fermi eigenstate. Higher means its probability is more concentrated across model sites.

MORE CONCENTRATED ↑12 STATES / MODEL
Selected stateTap a point on the chart
↗

The inverse participation ratio (IPR) increases as a state becomes more concentrated. Computed from twelve near-Fermi eigenstates per model; not physical travel distances.

03

What does it mean?

An ordered crystal has a regular repeating atomic pattern. Some of its modeled electronic states extend across many sites.

✳

Stay curious. Try a little experiment.

Switch from blue to green. Move across a peak. Tap a high dot, then a low one.
What changes—and what stays the same?

Behind the model Sources, assumptions & scientific context +

Original scientific plots

These graphs are recomputed from research/bismuth_heterostructure/run.py: a 48-site, four-state-per-site Hamiltonian, seed 83, with Gaussian DOS broadening σ = 0.065. The right chart shows the twelve eigenstates nearest zero energy per model. They are model proxies, not experimental spectra.

Blue: bulk A7 Bi proxy. Orange: ideal Bi/Mg superlattice proxy. Green: disordered Bi-Pb / Mg-Zn proxy. Energy is in model units.

Reproduce the browser dataset with python app/export_model.py. Within degenerate subspaces, eigenvectors and individual-state IPR can vary across numerical libraries; these charts use one reproducible exported basis. The animation maps each of the 48 model sites to patches of a conceptual 2D lattice. Selected eigenstates use their exported site weights; the energy dial controls an illustrative surface when no state is selected. The underlying Hamiltonian is a 1D chain. It does not reproduce the model geometry or depict electron trajectories.