English

Maximal lexicographic spectra and ranks for states with fixed uniform margins

Representation Theory 2018-11-28 v2

Abstract

We find the spectrum in maximal lexicographic order for quantum states ρABHAHB\rho_{AB}\in\mathcal{H}_A\otimes \mathcal{H}_B with margins ρA=1nIn\rho_A=\frac{1}{n}I_n and ρB=1mIm\rho_B=\frac{1}{m}I_m and discuss the construction of ρAB\rho_{AB}. By nonzero rectangular Kronecker coefficients, we give counterexamples for Klyachko's conjecture which says that a quantum state with maximal lexicographical spectrum has minimal rank among all states with given margins. Moreover, we show that quantum states with the maximal lexicographical spectrum are extreme points.

Keywords

Cite

@article{arxiv.1801.00986,
  title  = {Maximal lexicographic spectra and ranks for states with fixed uniform margins},
  author = {Xin Li},
  journal= {arXiv preprint arXiv:1801.00986},
  year   = {2018}
}

Comments

12pages, some proofs have been shortened and new references were added