Experimental Quantum Cloning of Single Photons

  title={Experimental Quantum Cloning of Single Photons},
  author={Antia Lamas-Linares and Christoph Simon and John C. Howell and Dirk Bouwmeester},
  pages={712 - 714}
Although perfect copying of unknown quantum systems is forbidden by the laws of quantum mechanics, approximate cloning is possible. A natural way of realizing quantum cloning of photons is by stimulated emission. In this context, the fundamental quantum limit to the quality of the clones is imposed by the unavoidable presence of spontaneous emission. In our experiment, a single input photon stimulates the emission of additional photons from a source on the basis of parametric down-conversion… 
Cloning of Quantum Entanglement.
Results show that one maximally entangled photon pair can be broadcast into two entangled pairs, both with state fidelities above 50%.
Experimental demonstration of entanglement-enabled universal quantum cloning in a circuit
No-cloning theorem forbids perfect cloning of an unknown quantum state. A universal quantum cloning machine (UQCM), capable of producing two copies of any input qubit with the optimal fidelity, is of
Applications of quantum cloning
Quantum Cloning Machines (QCMs) allow for the copying of information, within the limits imposed by quantum mechanics. These devices are particularly interesting in the high-gain regime, i.e., when
Optical implementations of the optimal phase-covariant quantum cloning machine
We propose two simple implementations of the optimal symmetric 1{yields}2 phase-covariant cloning machine for qubits. The first scheme is designed for qubits encoded into polarization states of
Realization Of Universal Quantum Cloning and of the Not Gate by Optical Parametric Amplification
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Experimental reversion of the optimal quantum cloning and flipping processes
The quantum cloner machine maps an unknown arbitrary input qubit into two optimal clones and one optimal flipped qubit. By combining linear and nonlinear optical methods we experimentally implement a
Cavity QED scheme for realizing the optimal universal quantum cloning of the polarization state of photons
We propose a scheme to realize the optimal universal quantum cloning of the polarization state of the photons in context of a microwave cavity quantum electrodynamics. The scheme is based on the
Cloning of single photon by high gain amplifier
In the last years the simultaneous realization of the optimal cloning and optimal flipping of an input qubit has been reported adopting a quantum injected optical parametric amplifier. The previous


Optical realization of universal quantum cloning
Beyond the no-cloning theorem, the universal symmetric quantum cloning machine was first addressed by Buzek and Hillery. Here, we realized the one-to-two qubits Buzek-Hillery cloning machine with
Optimal quantum cloning via stimulated emission
It is shown that optimal universal quantum cloning can be realized via stimulated emission and a scheme based on stimulated parametric down-conversion is presented, which implements the optimal universal NOT operation.
Quantum copying: Beyond the no-cloning theorem.
  • Buzek, Hillery
  • Physics
    Physical review. A, Atomic, molecular, and optical physics
  • 1996
It is shown that there exists a ‘‘universal quantum-copying machine’’ ~i.e., transformation! which approximately copies quantum-mechanical states such that the quality of its output does not depend on the input.
A single quantum cannot be cloned
If a photon of definite polarization encounters an excited atom, there is typically some nonvanishing probability that the atom will emit a second photon by stimulated emission. Such a photon is
Optimal Universal Quantum Cloning and State Estimation
We derive a tight upper bound for the fidelity of a universal N ! M qubit cloner, valid for any M $ N, where the output of the cloner is required to be supported on the symmetric subspace. Our proof
Optimal manipulations with qubits: Universal-NOT gate
The universal-NOT gate is introduced that takes as an input a qubit in an arbitrary state and generates an output that is as close as possible to the orthogonal state of Psi.
Cloning and quantum computation
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