Efficient Decomposition of Unitary Matrices in Quantum Circuit Compilers

Anna M. Krol*, Aritra Sarkar, Imran Ashraf, Zaid Al-Ars, Koen Bertels

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)
148 Downloads (Pure)


Unitary decomposition is a widely used method to map quantum algorithms to an arbitrary set of quantum gates. Efficient implementation of this decomposition allows for the translation of bigger unitary gates into elementary quantum operations, which is key to executing these algorithms on existing quantum computers. The decomposition can be used as an aggressive optimization method for the whole circuit, as well as to test part of an algorithm on a quantum accelerator. For the selection and implementation of the decomposition algorithm, perfect qubits are assumed. We base our decomposition technique on Quantum Shannon Decomposition, which generates O(344n) controlled-not gates for an n-qubit input gate. In addition, we implement optimizations to take advantage of the potential underlying structure in the input or intermediate matrices, as well as to minimize the execution time of the decomposition. Comparing our implementation to Qubiter and the UniversalQCompiler (UQC), we show that our implementation generates circuits that are much shorter than those of Qubiter and not much longer than the UQC. At the same time, it is also up to 10 times as fast as Qubiter and about 500 times as fast as the UQC.
Original languageEnglish
Article number759
Pages (from-to)1-20
Number of pages20
JournalApplied Sciences
Issue number2
Publication statusPublished - 2022


  • Quantum Shannon Decomposition
  • Quantum circuit optimization
  • Quantum compiler
  • Quantum computing
  • Unitary decomposition


Dive into the research topics of 'Efficient Decomposition of Unitary Matrices in Quantum Circuit Compilers'. Together they form a unique fingerprint.

Cite this