Biomedical subjects

Holger F Hofmann

Publications and source records attributed to Holger F Hofmann.

4 recordsLinked to original sources

PubMed2005

Demonstration of an optical quantum controlled-NOT gate without path interference.

We report the first experimental demonstration of an optical quantum controlled-NOT gate without any path interference, where the two interacting path interferometers of the original proposals have been replaced by three partially polarizing beam splitters with suitable polarization dependent transmittance and reflectance. The performance of the device is evaluated using a recently proposed method, by which the quantum process fidelity and the entanglement capability can be estimated from the 32 measurement results of two classical truth tables, significantly less than the 256 measurement results required for full quantum tomography.

Journal Article↗

PubMed2005

Complementary classical fidelities as an efficient criterion for the evaluation of experimentally realized quantum operations.

It is shown that a good estimate of the fidelity of an experimentally realized quantum process can be obtained by measuring the outputs for only two complementary sets of input states. The number of measurements required to test a quantum network operation is therefore only twice as high as the number of measurements required to test a corresponding classical system.

Journal Article↗

PubMed2004

Distinguishing genuine entangled two-photon-polarization sfrom independently generated pairs of entangled photons.

A scheme to distinguish entangled two-photon-polarization (ETP) states from two independent entangled one-photon-polarization (EOP) states is proposed. Using this scheme, the experimental generation of ETP by parametric down-conversion is confirmed through the anticorrelations among three orthogonal two-photon-polarization states. The estimated fraction of ETP among the correlated photon pairs is 37% in the present experimental setup.

Journal Article↗

PubMed2002

Quantum filter for nonlocal polarization properties of photonic qubits.

We present an optical filter that transmits photon pairs only if they share the same horizontal or vertical polarization, without decreasing the quantum coherence between these two possibilities. Various applications for entanglement manipulations and multiphoton qubits are discussed.

Journal Article↗