Engineering interactions for quasiperfect transfer of polariton states through nonideal bosonic networks of distinct topologies

Abstract

We present a scheme for quasiperfect transfer of polariton states from a sender to a spatially separated receiver, both composed of high-quality cavities filled by atomic samples. The sender and the receiver are connected by a nonideal transmission channel -the data bus-modelled by a network of lossy empty cavities. In particular, we analyze the influence of a large class of data-bus topologies on the fidelity and transfer time of the polariton state. Moreover, we also assume dispersive couplings between the polariton fields and the data-bus normal modes in order to achieve a tunneling-like state transfer. Such a tunneling-transfer mechanism, by which the excitation energy of the polariton effectively does not populate the data-bus cavities, is capable of attenuating appreciably the dissipative effects of the data-bus cavities. After deriving a Hamiltonian for the effective coupling between the sender and the receiver, we show that the decay rate of the fidelity is proportional to a cooperativity parameter that weighs the cost of the dissipation rate against the benefit of the effective coupling strength. The increase of the fidelity of the transfer process can be achieved at the expense of longer transfer times. We also show that the dependence of both the fidelity and the transfer time on the network topology is analyzed in detail for distinct regimes of parameters. It follows that the data-bus topology can be explored to control the time of the state-transfer process.

Collectively Enhanced Interactions in Solid-State Spin Qubits

“…By contrast to our previous discussions of dipolar spin chains, where we made an explicit nearest-neighbor assumption, which truncates the otherwise 1/r 3 interaction, many bosonic oscillator systems are often naturally nearest neighbor. For example, the realization of such coupled oscillators is currently being explored in systems such as cavity arrays [23][24][25], nanomechanical oscillators [63,64], Josephson junctions [65][66][67], and optomechanical crystals [68].…”

“…As a result, there has been tremendous recent interest in quantum data buses, which enable universal gates between physically separated quantum registers [9][10][11][12][13][14][15][16]. Such data buses have been proposed in systems ranging from trapped ions [17][18][19] and superconducting flux qubits [20][21][22] to coupled cavity arrays [23][24][25] and solid-state spin chains [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Prior proposals have focused on achieving perfect state transfer using either initialized [28,29,36,39], engineered [31,41,42], or dynamically controlled quantum channels [43][44][45][46].…”

Multi-photon quantum communication in quantum networks

“…Extensions.-While the case of a multi-dimensional hyercube has been chosen to focus on, we extend this result to a one-dimensional (1D) coupled-resonators and the realization of such resonator chain can be explored in many physical systems [35][36][37][38][39][40]. If K uv (G) = κ u−1 δ u,v+1 + κ u δ u,v−1 in the Hamiltonian of Eq.…”

Colored channels for high-fidelity information transfer and processing between remote multi-branch quantum circuits

“…Aiming to optimize the control required for communication between distant nodes in a QC, the research effort devoted to state transfer has led to the necessary and sufficient conditions, within spin [2] and resonator networks [3], for it to demonstrate that perfect transfer can occur in an entire class of topologies [4]. State transfer through realistic noise channels has also been addressed within spin chains [5,6] and a protocol for quasi-perfect state transfer in a network of dissipative resonators [7,8] seems to broaden the perspective on the subject of decoherence-(quasi-)free subspaces [9]. In a more recent contribution [10], the process of quasi-perfect remote state transfer has been formally characterized as a nonlocal tunneling process where -by analogy with the tunneling effect in a double-well barrier-the overlap between distant sender and the receiver wave functions is indirectly mediated by the normal modes of the data bus (DB), i.e., the transmission kernel of the network.…”

“…Such a strategy leads to a threebody Hamiltonian -taking into account the sender, the receiver, and the "mathematical" system associated with the selected normal mode of the DB-which governs the perfect state transfer in the case of ideal networks. For nonideal networks, the perfect state transfer gives way to a process whose nonunity fidelity can be optimized through the above-mentioned nonlocal tunnelling mechanism [8,10], ensuring that the state goes directly from the sender to the receiver without populating the nonideal DB. As demonstrated in refs.…”