Dissipative ground-state preparation of a spin chain by a structured environment

CECILIA CORMICK; ALEJANDRO BERMUDEZ; SUSANA F. HUELGA; MARTIN B. PLENIO

NEW JOURNAL OF PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2013 vol. 15 p. 1 - 30

1367-2630

We propose a dissipative method to prepare the ground state of the isotropic XY spin Hamiltonian in a transverse field. Our model consists of a spin chain with nearest-neighbor interactions and an additional collective coupling of the spins to a damped harmonic oscillator. The latter provides an effective environment with a Lorentzian spectral density and can be used to drive the chain asymptotically toward its multipartite-entangled ground state at a rate that depends on the degree of non-Markovianity of the evolution. We also present a detailed proposal for the experimental implementation with a chain of trapped ions. The protocol does not require individual addressing, concatenated pulses, or multi-particle jump operators, and is capable of generating the desired target state in small ion chains with very high fidelities.