This is the flat, 2D twin of the 3D holographic tensor-network simulator: the exact same MERA-style binary tree, drawn as a radial diagram instead of an extruded 3D tree — the boundary chain of N entangled qubits sits on the outer ring, and each ring stepping inward is one layer of the fictitious "bulk" that geometrises the entanglement pattern of the layer below, collapsing at the centre to the tree's root. This is essentially the ground-plan view of the 3D scene: the 3D layout already places every node's radius from the centre purely as a function of its layer, so nothing about the network's structure is lost by dropping the vertical axis.
The Ryu–Takayanagi conjecture states that the entanglement entropy of a boundary region A equals the area of the minimal bulk surface homologous to A, in Planck units:
S(A) = Area(γ_A) / 4G_N
In a discrete tensor network this becomes a graph theorem (Bao, Pollack, Remmen 2015 — random tensor networks): the area is replaced by a minimal edge cut through the bulk graph separating region A's legs from the rest, each severed bond contributing log₂χ bits (χ = bond dimension):
S(A) = min-cut(A, Ā) · log₂χ [max-flow / min-cut theorem]
This simulator builds the tree, then runs a real Edmonds–Karp max-flow from a super-source wired to A's boundary legs to a super-sink wired to the rest — the resulting min cut (red edges) is the discrete Ryu–Takayanagi surface.
- Interval size / start — choose which contiguous block of boundary qubits is "region A".
- Network depth — more layers ⇒ more boundary sites (N = 2^depth) and a deeper bulk.
- Bond dimension χ — how much entanglement a single bulk bond can carry; scales S(A) linearly.
- Drag / scroll — pan and zoom the diagram; "Reset view" recentres it.
The signature holographic result you can see directly: S(A) grows with the boundary of the region (a near-constant number of cut edges once A is a small contiguous block), not with its volume — the same area-law scaling that makes black-hole entropy proportional to horizon area rather than interior volume.