Quantum computers in phase space
Abstract
We represent both the states and the evolution of a quantum computer in phase space using the discrete Wigner function. We study properties of the phase space representation of quantum algorithms: apart from analyzing important examples, such as the Fourier transform and Grover's search, we examine the conditions for the existence of a direct correspondence between quantum and classical evolutions in phase space. Finally, we describe how to measure directly the Wigner function in a given phasespace point by means of a tomographic method that, itself, can be interpreted as a simple quantum algorithm.
 Publication:

Physical Review A
 Pub Date:
 June 2002
 DOI:
 10.1103/PhysRevA.65.062309
 arXiv:
 arXiv:quantph/0204149
 Bibcode:
 2002PhRvA..65f2309M
 Keywords:

 03.67.Hk;
 02.70.c;
 03.65.Ta;
 Quantum communication;
 Computational techniques;
 simulations;
 Foundations of quantum mechanics;
 measurement theory;
 Quantum Physics
 EPrint:
 16 pages, 7 figures, to appear in Phys Rev A