Part 3 · benchmark design
To ask a serious scaling question, the project moves from two bosonic modes to seeded non-Clifford dynamics on a structured 61-qubit graph.
What HaPPY contributes
The original HaPPY tensor network is a toy model of holographic quantum error correction: bulk degrees of freedom are encoded at a boundary. This project uses the graph generated by a layered HaPPY construction as the interaction geometry for a dynamic circuit. It does not claim that the circuit is a model of real spacetime.
The frozen instance
- boundary size N = 145;
- 61 dynamic bulk qubits and 80 bulk edges;
- seed 260814;
- non-Clifford Floquet layers;
- 13 X, 13 Z and 16 ZZ probes.
Freezing the seed and the observable list matters. Without that step it is too easy to move the goalposts after discovering which observables are easy or which circuits happen to fit the hardware.
A useful benchmark needs two tasks
Local expectation values and global sampling are different computational problems. A full state may be difficult to represent while one local observable has a small backwards causal cone. The repository therefore reports exactly which output is requested and never transfers a hardness conclusion from one task to another.
Sources and reproducibility
- Bose et al., A Spin Entanglement Witness for Quantum Gravity
- Marletto & Vedral, Gravitationally Induced Entanglement
- Sabín, Digital quantum simulation of quantum gravitational entanglement
- Pastawski et al., Holographic quantum error-correcting codes
- IBM Quantum documentation: ZNE and PEA
- Public code, numerical reports and full 42-value table on GitHub
Project status: 14 August 2026. Numerical values come from the frozen public research artifacts; claim boundaries are deliberately preserved.