Quantum Optics in Maxwell's Fish Eye Lens with Single Atoms and Photons

We investigate the quantum optical properties of Maxwell's two-dimensional fish eye lens at the single-photon and single-atom level. We show that such a system mediates effectively infinite-range dipole-dipole interactions between atomic qubits, which can be used to entangle multiple pairs of distant qubits. We find that the rate of the photon exchange between two atoms, which are detuned from the cavity resonances, is well described by a model, where the photon is focused to a diffraction-limited area during absorption. We consider the effect of losses on the system and study the fidelity of the entangling operation via dipole-dipole interaction. We derive our results analytically using perturbation theory and the Born-Markov approximation and then confirm their validity by numerical simulations. We also discuss how the two-dimensional Maxwell's fish eye lens could be realized experimentally using transformational plasmon optics.Comment: 20 pages, 7 figure

Symmetry-protected dissipative preparation of matrix product states

We propose and analyze a method for efficient dissipative preparation of matrix product states that exploits their symmetry properties. Specifically, we construct an explicit protocol that makes use of driven-dissipative dynamics to prepare the Affleck-Kennedy-Lieb-Tasaki (AKLT) states, which features symmetry-protected topological order and non-trivial edge excitations. We show that the use of symmetry allows for robust experimental implementation without fine-tuned control parameters. Numerical simulations show that the preparation time scales polynomially in system size $n$. Furthermore, we demonstrate that this scaling can be improved to $\mathcal{O}(\log^2n)$ by using parallel preparation of AKLT segments and fusing them via quantum feedback. A concrete scheme using excitation of trapped neutral atoms into Rydberg state via Electromagnetically Induced Transparency is proposed, and generalizations to a broader class of matrix product states are discussed