Electronic Proceedings in Theoretical Computer Science (Jan 2019)

ReQWIRE: Reasoning about Reversible Quantum Circuits

  • Robert Rand,
  • Jennifer Paykin,
  • Dong-Ho Lee,
  • Steve Zdancewic

DOI
https://doi.org/10.4204/EPTCS.287.17
Journal volume & issue
Vol. 287, no. Proc. QPL 2018
pp. 299 – 312

Abstract

Read online

Common quantum algorithms make heavy use of ancillae: scratch qubits that are initialized at some state and later returned to that state and discarded. Existing quantum circuit languages let programmers assert that a qubit has been returned to the |0> state before it is discarded, allowing for a range of optimizations. However, existing languages do not provide the tools to verify these assertions, introducing a potential source of errors. In this paper we present methods for verifying that ancillae are discarded in the desired state, and use these methods to implement a verified compiler from classical functions to quantum oracles.