testing
How OQFT Was Tested, Matrices, Random Inputs and the Wraparound Edge
A circuit generator can produce something that looks fine, loads fine, and computes the wrong thing. The only way to know is to run the circuit and compare. OQFT does …
Version 0.3, free and open source
The quantum Fourier transform, in log depth
OQFT builds the optimistic quantum Fourier transform: a circuit that's right on almost every input, uses no spare qubits, and has a depth that barely grows with the register. Generate it as OpenQASM 3, count its gates, and check it on a simulator.
198
Depth of the optimistic QFT on 2,048 qubits. The textbook circuit needs 4,096
20x
Fewer gates at 2,048 qubits: about 104,000 instead of 2.1 million
0 spare
Extra qubits needed. The circuit runs on the register itself
Apache 2.0
License for all of the code
Counts from oqft stats at epsilon 0.01, where every gate counts as one layer. The recorded results are on GitHub.
Notes and releases
explainers
Optimistic Quantum Circuits Explained, Why a QFT That Is Almost Always Right Is Enough
Ask a circuit designer for a quantum Fourier transform and they’ll want it right on every input. That’s the normal bar. A circuit is a fixed piece of …
releases
OQFT 0.3 Cuts QFT Depth From 4096 to 198 on a 2048-Qubit Register
The quantum Fourier transform sits in the middle of Shor’s algorithm. Build it the textbook way on 2,048 qubits, the size you’d need for a 2048-bit RSA key, …
the name
What OQFT Stands For, the Optimistic Quantum Fourier Transform
OQFT is four letters and one idea. The last three, QFT, are the quantum Fourier transform, one of the most used building blocks in quantum computing. The O is the new …
Questions or ideas?
If you work on quantum algorithms, compilers or post-quantum planning and OQFT nearly does what you need, write in.