Alladi Ramakrishnan Hall

Long-range multipartite entanglement from a local drive

Shovan Dutta

Raman Research Institute

I will talk about star-shaped networks of qubits, composed of identical spin-1/2 chains coupled to a central spin, that can be incoherently driven at the centre to generate strong multipartite entanglement across the network. In particular, by mediating the central coupling through auxiliary spins, one can make the networks free fermionic and controllably project the outermost qubits onto maximally-entangled W states. On the other hand, for direct coupling to the centre the networks do not reduce to free particles but nonetheless possess a hidden SO(N)-type symmetry that protects a large number of steady states, from minimally to maximally entangled. Some of these findings may be realisable with superconducting qubits in present-day setups.