Title
Constant gap between conventional strategies and those based on C*-dynamics for self-embezzlement
Abstract
We consider a bipartite transformation that we call self-embezzlement and use it to prove a constant gap between the capabilities of two models of quantum information: the conventional model, where bipartite systems are represented by tensor products of Hilbert spaces; and a natural model of quantum information processing for abstract states on C*-algebras, where joint systems are represented by tensor products of C*-algebras. We call this the C*-circuit model and show that it is a special case of the commuting-operator model (in that it can be translated into such a model). For the conventional model, we show that there exists a constant epsilon(0) > 0 such that self-embezzlement cannot be achieved with precision parameter less than epsilon(0) (i.e., the fidelity cannot be greater than 1 - epsilon(0)); whereas, in the C*-circuit model-as well as in a commuting-operator model-the precision can be 0 (i.e., fidelity 1). Self-embezzlement is not a non-local game, hence our results do not impact the celebrated Connes Embedding conjecture. Instead, the significance of these results is to exhibit a reasonably natural quantum information processing problem for which there is a constant gap between the capabilities of the conventional Hilbert space model and the commuting-operator or C*-circuit model.
Year
DOI
Venue
2022
10.22331/q-2022-07-07-755
QUANTUM
DocType
Volume
ISSN
Journal
6
2521-327X
Citations 
PageRank 
References 
0
0.34
0
Authors
4
Name
Order
Citations
PageRank
Richard Cleve100.34
Benoit Collins200.34
Li Liu318112.42
Vern I. Paulsen400.68