179 research outputs found
Scheme for implementing quantum information sharing via tripartite entangled state in cavity QED
We investigate economic protocol to securely distribute and reconstruct a
single-qubit quantum state between two users via a tripartite entangled state
in cavity QED. Our scheme is insensitive to both the cavity decay and the
thermal field.Comment: Final version to appear in Physica
Nonlocal Gate Of Quantum Network Via Cavity Quantum Electrodynamics
We propose an experimentally feasible scheme to realize the nonlocal gate
between two different quantum network nodes. With an entanglement-qubit (ebit)
acts as a quantum channel, our scheme is resistive to actual environment noise
and can get high fidelity in current cavity quantum electrodynamics (C-QED)
system.Comment: 5 pages, 3 figures, 1 tabl
Deterministic amplification of Schroedinger cat states in circuit quantum electrodynamics
We propose a dynamical scheme for deterministically amplifying photonic
Schroedinger cat states based on a set of optimal state-transfers. The scheme
can be implemented in strongly coupled qubit-cavity systems and is well suited
to the capabilities of state of the art superconducting circuits. The ideal
analytical scheme is compared with a full simulation of the open
Jaynes-Cummings model with realistic device parameters. This amplification tool
can be utilized for practical quantum information processing in non-classical
continuous-variable states.Comment: A revised manuscript has 6 figure
Advances in Quantum Teleportation
Quantum teleportation is one of the most important protocols in quantum
information. By exploiting the physical resource of entanglement, quantum
teleportation serves as a key primitive in a variety of quantum information
tasks and represents an important building block for quantum technologies, with
a pivotal role in the continuing progress of quantum communication, quantum
computing and quantum networks. Here we review the basic theoretical ideas
behind quantum teleportation and its variant protocols. We focus on the main
experiments, together with the technical advantages and disadvantages
associated with the use of the various technologies, from photonic qubits and
optical modes to atomic ensembles, trapped atoms, and solid-state systems.
Analysing the current state-of-the-art, we finish by discussing open issues,
challenges and potential future implementations.Comment: Nature Photonics Review. Comments are welcome. This is a
slightly-expanded arXiv version (14 pages, 5 figure, 1 table
Efficient Teleportation between Remote Single-Atom Quantum Memories
We demonstrate teleportation of quantum bits between two single atoms in
distant laboratories. Using a time-resolved photonic Bell-state measurement, we
achieve a teleportation fidelity of (88.0+/-1.5)%, largely determined by our
entanglement fidelity. The low photon collection efficiency in free space is
overcome by trapping each atom in an optical cavity. The resulting success
probability of 0.1% is almost 5 orders of magnitude larger than in previous
experiments with remote material qubits. It is mainly limited by photon
propagation and detection losses and can be enhanced with a cavity-based
deterministic Bell-state measurement.Comment: 7 pages, 4 figures, 1 tabl
Hybrid quantum repeater based on resonant qubit-field interactions
We propose a hybrid quantum repeater based on ancillary coherent field states
and material qubits coupled to optical cavities. For this purpose, resonant
qubit-field interactions and postselective field measurements are determined
which are capable of realizing all necessary two-qubit operations for the
actuation of the quantum repeater. We explore both theoretical and experimental
possibilities of generating near-maximally-entangled qubit pairs ()
over long distances. It is shown that our scheme displays moderately low
repeater rates, between and pairs per second, over
distances up to km, and it relies completely on current technology of
cavity quantum electrodynamics.Comment: 18 pages, 13 figures, corrected according to published Erratu
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