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We present photon-spin quantum-state-transfer (QST) approach. GaAs/AlGaAs-QW with g~0 showed nonlinear B-field dependence of spin precession, suggesting photon-to-nuclei polarization transfer. 2DEG with quantum-point-contact on InGaAs/InP showed telecomwavelength-sensitive quantum transport. Efficient/high-fidelity QST conditions were also found.
We have detected electromagnetically-induced transparency (EIT) in a cigar-shaped MOT. The asymmetric shape of probe absorption as a function of frequency is consistent with enhancement of optical depth due to wave guiding of the probe.
We propose a quantum key distribution scheme using the spatial properties of the entangled photon pairs generated from parametric downconversion. The security of this scheme is guaranteed by the distributed entanglement.
ldquoZero-meanrdquo optical potentials are used to manipulate dephasing of ultra-cold atoms confined in atom-optical billiards. Generic and non-generic perturbations result in qualitatively different dephasing properties. Different phase-space regimes are probed and identified.
Fringes of total atomic density produced in an atom interferometer consisting of two off-resonant standing wave pulses were directly imaged using an ldquooptical maskrdquo technique. Fringe periods with integer fractions of the standing-wave period were observed.
We observe spontaneous symmetry breaking in a 87Rb spinor Bose condensate quenched across a quantum phase transition. This quench causes inhomogeneous ferromagnetic regions and topological defects to form in a magnetic quantum fluid.
Sequential quantum teleportation for continuous variables is experimentally demonstrated. By using two high fidelity teleporters, an unknown coherent state is teleported twice and fidelity is F = 0.53plusmn0.2.We show the measurement results using optical homodyne tomography.
We report on the scalable and deterministic generation and tomographic characterization of entangled states of up to 8 trapped ions and experiments towards entangling ions and photons.
Full quantum theory of the optical two-qubit quantum phase gate for single photons is formulated. Trade-off between the conditional phase shift and gate fidelity is found, but could be compensated in transient regime.
We report our progress towards the realization of a tunable and narrow-band source of correlated photons for coherent manipulation of cold atoms, using a combination of four-wave mixing and electromagnetically induced transparency.
An individual incoherent eavesdropping on a two-way quantum protocol for deterministic communication without entanglement is stimulated. The results show that the protocol remains secure regardless of the noise caused by the eavesdropper.
We study the quantum state transfer (QST) from a photon polarization to an electron spin. We reveal the condition for high-yield and high-fidelity QST by solving the time-dependent Schrodinger equation.
We theoretically present that generation of entangled-photon pairs from biexcitons in a quantum well is dramatically enhanced by using a microcavity. Itpsilas optimal condition is qualitatively understood from the characteristic feature of the cavity QED.
We perform an experimental demonstration of the physical mechanism utilized by most three party secret sharing protocols. By local operations at distant locations, we reduce and restore entanglement in a polarization entangled bipartite qubit system.
We propose a new sensing method based on two quantum entangled beams. The effects caused by inserting polarizer or DNA solution into one beam can be also detected in the other undisturbed entangled beam.
We experimentally show that nonzero pump-beam angular momentum plays a different role in type-II parametric down-converstion than in type-I. We explore the reason(s) why pump-beam profile does not appear in coincidence imaging of type-II down-converstion.
We demonstrate theoretically the migration of entanglement of photon pairs produced in spontaneous parametric down-conversion from intensity to phase, and propose two experiments to observe the migration and to detect the ldquomissingrdquo entanglement.
We realize image amplification in the continuous wave regime within an optical parametric oscillator bellow threshold. We show that its noise figure is better than that of a classical amplifier, demonstrating its quantum multimode operation.
We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter.
The Fuchs-Peres-Brandt (FPB) probe realizes the most powerful individual attack on BB84 quantum key distribution. A physical simulation of the FPB-probe attack using single-photon two-qubit quantum logic is described.
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