@article{1586626,
abstract = {Consider a mixed quantum mechanical state, describing a statistical ensemble in terms of an arbitrary density operator rho of low purity, tr rho(2) << 1, and yielding the ensemble averaged expectation value tr(rho A) for any observable A. Assuming that the given statistical ensemble rho is generated by randomly sampling pure states vertical bar psi > according to the corresponding so-called Gaussian adjusted projected measure (Goldstein et al. in J. Stat. Phys. 125:1197, 2006), the expectation value is shown to be extremely close to the ensemble average tr(rho A) for the overwhelming majority of pure states vertical bar psi > and any experimentally realistic observable A. In particular, such a 'typicality' property holds whenever the Hilbert space H of the system contains a high dimensional subspace H+ subset of H with the property that all vertical bar psi > epsilon H+ are realized with equal probability and all other vertical bar psi > epsilon H are excluded.},
author = {Reimann, Peter},
issn = {1572-9613},
journal = {JOURNAL OF STATISTICAL PHYSICS},
keyword = {measures, Gaussian, quantum statistical mechanics, microcanonical density matrices, quantum ensemble theory},
number = {5},
pages = {921--935},
publisher = {SPRINGER},
title = {{Typicality of pure states randomly sampled according to the Gaussian adjusted projected measure}},
doi = {10.1007/s10955-008-9576-1},
volume = {132},
year = {2008},
}