We present a scheme to generate a continuous variable (CV) multipartite entangled state using an array of plasmonic graphene waveguides that are activated by nonclassical driving microwave modes. Within this scheme, we can exploit the interaction of two light fields coupled to the same microwave mode in each waveguide to produce any type of multipartite Gaussian entangled state. A teleportation network is illustrated using the resultant CV multipartite entangled state. In particular, the proposed setup enables coherent state teleportation across remotely connected nodes with fidelity above a threshold limit of 2/3, providing secure quantum teleportation networking even in the presence of losses.
We propose a quantum network consisting of optical waveguides in the linear regime for quantum state transfer. The circular topology of our network introduces novel functionalities that enable us to analytically identify the conditions under which perfect state transfer (PST) is achievable. We utilize the properties of the Fourier modes, in particular the zero Fourier modes, which provide a protected subspace for the efficient propagation of quantum states, resulting in PST to the diametrically opposite site in a network with any number of sites
N=4n. The coupling profiles in the photonic network modulate the number of zero-energy eigenmodes, with uniform couplings yielding more than evanescent ones, confirming that the expedition of observed PST originates from the collapse of the eigenvalue spectrum into three distinct eigenvalue blocks, including
N/2 manifolds of zero Fourier modes. We investigate PST in both discrete- and continuous-variable input regimes, using single photon state, Schrödinger cat states, and two-mode squeezed vacuum state. Our findings apply to the engineering of quantum networks and photonic lattices, paving the way for applications in controlled routing in integrated quantum circuits.
We study the possibility of generating continuous-variable (CV) entanglement on an integrated chip through nonlinear optical waveguides coupled in a circular array. We show the simultaneous generation and manipulation of multimode CV entangled states of light in χ (2) nonlinear circular arrays (NCAs), a feat unattainable with linear optical waveguides and bulk optical elements. These weakly coupled integrated waveguide arrays are compact and can be fabricated using the femtosecond laser writing technique. This technique offers interferometric stability, scalability, and less sensitivity to decoherence. Our study investigates the potential of NCA to generate bipartite and tripartite CV entanglement. We present analytical results and numerical simulations based on coupled-mode equations for the evolution of field operators. Our findings suggest promising applications of compact on-chip sources in various photonic quantum technologies, such as communication, computing, and networking.