English

Use of Quantum Sampling to Calculate Mean Values of Observables and Partition Function of a Quantum System

Quantum Physics 2010-11-10 v3

Abstract

We describe an algorithm for using a quantum computer to calculate mean values of observables and the partition function of a quantum system. Our algorithm includes two sub-algorithms. The first sub-algorithm is for calculating, with polynomial efficiency, certain diagonal matrix elements of an observable. This sub-algorithm is performed on a quantum computer, using quantum phase estimation and tomography. The second sub-algorithm is for sampling a probability distribution. This sub-algorithm is not polynomially efficient. It can be performed either on a classical or a quantum computer, but a quantum computer can perform it quadratically faster.

Keywords

Cite

@article{arxiv.0912.4402,
  title  = {Use of Quantum Sampling to Calculate Mean Values of Observables and Partition Function of a Quantum System},
  author = {Robert R. Tucci},
  journal= {arXiv preprint arXiv:0912.4402},
  year   = {2010}
}

Comments

V1-12 pages(5 files: 1.tex, 3 .sty, 1 .eps);V2-minor changes;V3-minor changes and extension of scenario(c)