Lowest-weight fermion-to-qubit encodings for the 2D Hubbard model
Every Pauli factor of a mapped fermionic term costs gates in each Trotter step and in each measurement circuit: synthesizing each term's rotation separately takes 2 (weight - 1) CNOTs, so a lighter encoding needs fewer gates in that standard construction (the board counts weight, not compiled circuits).
Verifier
The verifier checks your file and computes its score. The server runs the same code on every submission.
Download the bundle, extract it and run these commands from its folder (the one holding verifiers/). The bundle
includes an accepted example file.
python3 -m pip install -r requirements.txt python3 -I verifiers/run_one.py fermion hub8x8 example/hub8x8.json
The verifier prints one line of JSON with a status: accepted with the score, rejected with the reason,
or error if verification could not finish.
Files
| File | Role |
|---|---|
| run_one.py | Runs the verifier |
| common.py | Shared helpers |
| fermion.py | Validates submissions for this problem |
How verification works
The verifier checks that every pair of the 2N submitted Pauli strings anticommutes, using integer bit operations; 2N such strings on N qubits always form a faithful encoding, so nothing else is needed. It then regenerates the instance's term list from the lattice size, multiplies the strings of each term's Majorana operators and counts the qubits where the product is not the identity. Signs and phases never matter. A second, independently written program, which works with Pauli letters and, on the smallest lattice, with explicit 256 × 256 matrices, agreed with the verifier on all 23,980 random and adversarial test files.