Researchers from ParityQC and the University of Innsbruck have unveiled the most efficient implementation of the Quantum Fourier Transform (QFT) on a linear chain of qubits, eliminating the need for SWAP or Shuttling operations. Their breakthrough, detailed in the paper “SWAP-less Implementation of Quantum Algorithms,” introduces a novel approach that leverages parity quantum information flow to optimize the QFT for quantum systems with limited connectivity.
QFT is a fundamental algorithm in quantum computing, essential for algorithms like Shor’s and quantum optimization. Traditionally, implementing QFT on a linear qubit chain is challenging due to the need for gates to operate between non-adjacent qubits, typically addressed using SWAP or Shuttling operations. The new approach avoids this overhead by using entangling gates to transfer quantum information, leading to significant improvements in efficiency.
The novel implementation achieves a circuit depth of 5n−3 and requires n²−1 CNOT gates, setting new benchmarks in circuit depth and gate count for QFT on linear nearest-neighbor architectures. These improvements reduce the algorithm’s runtime and minimize errors, making the solution practical for near-term quantum applications.
For more information, see the paper “SWAP-less Implementation of Quantum Algorithms” on arXiv here and the press release from ParityQC here.
October 16, 2024