Pages on oqft.com

About

Mon, 01 Jan 0001 00:00:00 +0000

oqft.com is the home of OQFT, an open source toolkit for the optimistic quantum Fourier transform. It builds the circuit for any register size, writes it out as OpenQASM 3, counts its gates and depth, and checks it on a classical simulator against the exact transform.

The Name

OQFT stands for Optimistic Quantum Fourier Transform. The quantum Fourier transform, QFT for short, is the step in Shor’s factoring algorithm, and in quantum phase estimation, that turns a hidden repeating pattern into a number you can measure. “Optimistic” is the word the researchers who designed the fast version chose for circuits that are accurate on almost every input but give up on a small, predictable slice of them. The O in front is that trade.

Contact

Mon, 01 Jan 0001 00:00:00 +0000

oqft.com would like to hear from:

People building quantum compilers and toolchains who’d use an optimistic QFT as a building block.
Researchers who want a gate, an export format or a check that OQFT doesn’t have yet.
Anyone who found a bug. A circuit that doesn’t load, a count that looks off, an error you didn’t expect.

Write to info@oqft.com.

Bug reports are also welcome on GitHub. It helps to include what oqft version prints, the exact command you ran and what it printed.

Download OQFT

Mon, 01 Jan 0001 00:00:00 +0000

The oqft command is one file with nothing else to install. Each archive below holds it with its license files. The links always point to the latest release.

System	Download
Linux, x86-64	oqft_linux_amd64.tar.gz
Linux, ARM64	oqft_linux_arm64.tar.gz
macOS, Apple silicon	oqft_darwin_arm64.tar.gz
macOS, Intel	oqft_darwin_amd64.tar.gz
Windows, x86-64	oqft_windows_amd64.zip

Checksums are in SHA256SUMS. Every release is listed on GitHub.

Install

On Linux or macOS:

tar -xzf oqft_linux_amd64.tar.gz
sudo mv oqft /usr/local/bin/
oqft version

The binaries are static, so they run on any Linux distribution. The macOS binaries aren’t signed by Apple, so macOS may block the first run. Allow it in System Settings under Privacy & Security, or run xattr -d com.apple.quarantine oqft. On Windows, unzip the archive and put oqft.exe in a folder on your PATH.

Quick Start

Mon, 01 Jan 0001 00:00:00 +0000

This page gets OQFT running and walks through its three commands: gen writes a circuit, stats counts it, and check tests it against the exact transform.

Install

Download the archive for your system from the download page, unpack it and put oqft on your PATH. Then:

oqft version

Write a Circuit

oqft gen prints a circuit as OpenQASM 3. The textbook QFT on four qubits:

oqft gen -n 4

The optimistic QFT on 128 qubits, with an error target of 0.01, saved to a file:

Reference

Mon, 01 Jan 0001 00:00:00 +0000

Everything oqft does, in one page. The quick start has worked examples.

Commands

Command	What it does
`oqft gen`	Writes a circuit as OpenQASM 3 to standard output
`oqft stats`	Compares gate counts and depth of the textbook and approximate QFT, and the optimistic QFT when `--eps` is given
`oqft check`	Measures each input’s error against the exact QFT on a simulator
`oqft version`	Prints the version
`oqft help`	Lists the commands

oqft gen

oqft gen --type qft|aqft|oqft -n N [--cutoff K] [--eps E]

Option	Meaning	Default
`-n`	Number of qubits. Required
`--type`	`qft` textbook, `aqft` approximate, `oqft` optimistic	`qft`
`--cutoff`	For `aqft`: the largest distance between two qubits that keeps its rotation	2
`--eps`	For `oqft`: the error target, between 0 and 1	0.01

oqft stats

oqft stats -n N [--cutoff K] [--eps E]

Prints counts of each gate, total gates, two-qubit gates and depth. With --eps it adds a line for the optimistic QFT at that error target.