CUGatesDensity—Quantum circuit analyser extended to density matrices

Abstract

CUGatesDensity is an extension of the original quantum circuit analyser CUGates (Loke and Wang, 2011) [7] to provide explicit support for the use of density matrices. The new package enables simulation of quantum circuits involving statistical ensemble of mixed quantum states. Such analysis is of vital importance in dealing with quantum decoherence, measurements, noise and error correction, and fault tolerant computation. Several examples involving mixed state quantum computation are presented to illustrate the use of this package. Program summaryProgram title: CUGatesDensity.mCatalogue identifier: AEPY_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEPY_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 5368No. of bytes in distributed program, including test data, etc.: 143994Distribution format: tar.gzProgramming language: Mathematica.Computer: Any computer installed with a copy of Mathematica 6.0 or higher.Operating system: Any system with a copy of Mathematica 6.0 or higher installed.Classification: 4.15.Nature of problem:To simulate arbitrarily complex quantum circuits comprised of single/multiple qubit and qudit quantum gates with mixed state registers.Solution method:A density matrix representation for mixed states and a state vector representation for pure states are used. The construct is based on an irreducible form of matrix decomposition, which allows a highly efficient implementation of general controlled gates with multiple conditionals.Running time:The examples provided in the notebook CUGatesDensity.nb take approximately 30 s to run on a laptop PC.