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Multi-level, multi-party singlets as ground states and their role in entanglement distribution

Christopher Hadley·Sougato Bose
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Abstract

We show that a singlet of many multi-level quantum systems arises naturally as the ground state of a physically-motivated Hamiltonian. The Hamiltonian simply exchanges the states of nearest-neighbours in some network of qudits (d-level systems); the results are independent of the strength of the couplings or the network's topology. We show that local measurements on some of these qudits project the unmeasured qudits onto a smaller singlet, regardless of the choice of measurement basis at each measurement. It follows that the entanglement is highly persistent, and that through local measurements, a large amount of entanglement may be established between spatially-separated parties for subsequent use in distributed quantum computation.

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Christopher Hadley, Sougato Bose. 2008-05-23. Multi-level, multi-party singlets as ground states and their role in entanglement distribution. https://doi.org/10.1103/physreva.77.050308

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