Computing with highly mixed states
Quantum Physics
2007-05-23 v1
Abstract
We consider quantum computing in the k-qubit model where the starting state of a quantum computer consists of k qubits in a pure state and n-k qubits in a maximally mixed state. We ask the following question: is there a general method for simulating an arbitrary m-qubit pure state quantum computation by a quantum computation in the k-qubit model? We show that, under certain constraints, this is impossible, unless m=O(k+ log n).
Cite
@article{arxiv.quant-ph/0003136,
title = {Computing with highly mixed states},
author = {Andris Ambainis and Leonard J. Schulman and Umesh Vazirani},
journal= {arXiv preprint arXiv:quant-ph/0003136},
year = {2007}
}
Comments
8 pages, 3 figures, to appear in proceedings of STOC'00