Namasi G. Sankar
Inside the framework

Four ideas, in motion

QUBO decomposition, the HADOF loop, quantum genome assembly, and the optimisation results they produce — animated, in the order they actually run.

01 · Decomposition

One big problem, many small ones

A QUBO over hundreds or thousands of variables is a dense matrix of pairwise couplings — far more than any current QPU can hold at once.

HADOF repeatedly carves out small, overlapping sub-blocks of that matrix, each one small enough to fit on a handful of physical qubits. Only the highlighted 3×3 block runs on the QPU at any moment — its couplings to the rest enter as expected values under the current marginals.

500variables, one problem
5qubits per sub-circuit
02 · The HADOF loop

Encode, solve, estimate, update, aggregate

Each sub-Hamiltonian is solved on real hardware, its samples turned into marginal probabilities for every variable, and those marginals fed back in to steer the next round of sub-problems.

The loop repeats until the global candidate solutions stop improving — a federated search, not a single giant circuit.

Read the full method →
Encode Solve Estimate Update Aggregate
TTTCCTCATG TCATGCAATT CAATTCAAAA CAAAACCATG CCATGTCCGT Assembled sequence TTTCCTCATGCAATTCAAAACCATGTCCGT
03 · Genome assembly

Reads → overlap graph → one sequence

Sequencing reads become nodes; suffix–prefix overlaps become edges. Reconstructing the genome means finding the right path through that graph — structurally a travelling-salesman problem.

HADOF solved this directly on real sequencing data: a 7.3 Mbp bacterial genome, a graph of 524 nodes and 2,313 edges, requiring far more qubits than any current device offers end to end.

524graph nodes
2,313edges / qubits needed
04 · Results

Decomposition holds up under noise

On IBM's 156-qubit ibm_aachen, topology-aware HADOF pushed sub-circuits from 5 qubits to 150, and SA-HADOF reached 98.5–98.8% of full Simulated Annealing's solution quality.

98.8%solution quality vs. full SA
8.6×faster than full SA
See the preliminary numbers →