English

Uniform Finite Generation of Compact Lie Groups and universal quantum gates

Quantum Physics 2007-05-23 v1

Abstract

Consider a compact connected Lie group GG and the corresponding Lie algebra L\cal L. Let {X1,...,Xm}\{X_1,...,X_m\} be a set of generators for the Lie algebra L\cal L. We prove that GG is uniformly finitely generated by {X1,...,Xm}\{X_1,...,X_m\}. This means that every element KGK \in G can be expressed as K=eXt1eXt2eXtlK=e^{Xt_1}e^{Xt_2} \cdot \cdot \cdot e^{Xt_l}, where the indeterminates XX are in the set {X1,...,Xm}\{X_1,...,X_m \}, ti\RRt_i \in \RR, i=1,...,li=1,...,l, and the number ll is uniformly bounded. This extends a previous result by F. Lowenthal in that we do not require the connected one dimensional Lie subgroups corresponding to the XiX_i, i=1,...,mi=1,...,m, to be compact. We discuss the consequence of this result to the question of universality of quantum gates in quantum computing.

Keywords

Cite

@article{arxiv.quant-ph/0111133,
  title  = {Uniform Finite Generation of Compact Lie Groups and universal quantum gates},
  author = {D. D'Alessandro},
  journal= {arXiv preprint arXiv:quant-ph/0111133},
  year   = {2007}
}