Eur. Phys. J. D 62, 449-456 (2011)
https://doi.org/10.1140/epjd/e2011-20070-y

Regular Article

Quantum computing with mixed states

¹ Physikalisches Institut, Heidelberg Universität, 69120 Heidelberg, Germany
² Department of Theoretical Physics, Belarussian State University, 4 Nezavisimosti av., 220030 Minsk, Belarus
³ Department of Physics, PO Box 3000, 90014 University of Oulu, Finland
⁴ GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany

^a e-mail: siomau@physi.uni-heidelberg.de

Received: 30 January 2011
Received in final form: 28 February 2011
Published online: 17 May 2011

Abstract

We discuss a model for quantum computing with initially mixed states. Although such a computer is known to be less powerful than a quantum computer operating with pure (entangled) states, it may efficiently solve some problems for which no efficient classical algorithms are known. We suggest a new implementation of quantum computation with initially mixed states in which an algorithm realization is achieved by means of optimal basis independent transformations of qubits.