Work

Optimal purification of thermal graph states

Year: 2006

Type: article

Abstract: In this paper, a purification protocol is presented and its performance is proven to be optimal when applied to a particular subset of graph states that are subject to local Z -noise. Such mixed states can be produced by bringing a system into thermal equilibrium, when it is described by a Hamiltonian which has a particular graph state as its unique ground state. From this protocol, we derive the exact value of the critical temperature T crit above which purification is impossible, as well as the related optimal purification rates. A possible simulation of graph Hamiltonians is proposed, which requires only bipartite interactions and local magnetic fields, enabling the tuning of the system temperature.

Source: New Journal of Physics

DOI: 10.1088/1367-2630/8/8/147

Authors: Alastair Kay, Jiannis K Pachos, Wolfgang Dür, Hans-J Briegel

Institutions: University of Cambridge, Austrian Academy of Sciences, Institute for Quantum Optics and Quantum Information Innsbruck, Universität Innsbruck

Language: English

Topic: Quantum Information and Cryptography

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,610

Funders: European Commission, Austrian Science Fund, Engineering and Physical Sciences Research Council