Multipartite entangled states in dipolar quantum simulators [article]

Tommaso Comparin, Fabio Mezzacapo, Tommaso Roscilde
2022 arXiv   pre-print
The scalable production of multipartite entangled states in ensembles of qubits is a fundamental function of quantum devices, as such states are an essential resource both for fundamental studies on entanglement, as well as for applied tasks. Here we focus on the U(1) symmetric Hamiltonians for qubits with dipolar interactions – a model realized in several state-of-the-art quantum simulation platforms for lattice spin models, including Rydberg-atom arrays with resonant interactions. Making use
more » ... f exact and variational simulations, we theoretically show that the non-equilibrium dynamics generated by this lattice spin Hamiltonian shares fundamental features with that of the one-axis-twisting model, namely the simplest interacting collective-spin model with U(1) symmetry. The evolution governed by the dipolar Hamiltonian generates a cascade of multipartite entangled states – spin-squeezed states, Schrödinger's cat states, and multi-component superpositions of coherent spin states. Investigating systems with up to N=144 qubits, we observe full scalability of the entanglement features of these states directly related to metrology, namely scalable spin squeezing at an evolution time O(N^1/3); and Heisenberg scaling of sensitivity of the spin parity to global rotations for cat states reached at times O(N). Our results suggest that the native Hamiltonian dynamics of state-of-the-art quantum simulation platforms, such as Rydberg-atom arrays, can act as a robust source of multipartite entanglement.
arXiv:2205.03910v1 fatcat:ozqsq3coirfvvhjeny3rh5aswm