58 research outputs found
Towards quantum frequency combs: boosting the generation of highly nonclassical light states by cavity-enhanced parametric down-conversion at high repetition rates
We demonstrate the generation of multi-photon quantum states of light by
cavity-enhanced parametric down-conversion in the high-repetition-rate pulsed
regime. An external enhancement cavity resonant with the spectral comb of modes
of a mode-locked pump laser provides a coherent build-up of the pump intensity
and greatly enhances the parametric gain without sacrificing its high
repetition rate and comb structure. We probe the parametric gain enhancement by
the conditional generation and tomographic analysis of two-photon Fock states.
Besides its potential impact to efficiently generate highly-nonclassical or
entangled multi-photon states in many existing experimental setups, this scheme
opens new and exciting perspectives towards the combination of quantum and comb
technologies for enhanced measurements and advanced quantum computation
protocols.Comment: 5 pages 3 figures; updated with major additions, added references,
and changed title. Accepted for publication in Physical Review
Generating Discorrelated States for Quantum Information Protocols by Coherent Multimode Photon Addition
AbstractIt is demonstrated that the recently developed technique of delocalized single photon addition may generate discorrelation, a new joint statistical property of multimode quantum light states, whereby the number of photons in each mode can take any value individually, but two modes together never exhibit the same. By coherently adding a single photon to two identical coherent states of light in different temporal modes, the first experimental observation of discorrelation is provided. The capability of manipulating this statistical property has applications in scenarios involving the secure distribution of information among untrusted parties, like in the so‐called "mental poker" games
A Vision-Based Referencing Procedure for Cable-Driven Parallel Manipulators
In the last three decades, cable-driven parallel robots (CDPRs) have captured a growing attention in the robotics field. Indeed, they promise to bring automation in fields where it is not affirmed yet, granting ease of scaling and reconfigurability. For large-workspace cable robots, accuracy is an important issue. In this paper, a look-and-move procedure is proposed, based on a wireless camera, to refer the coordinate frame of the CDPR platform to another known coordinate frame. Two sample cases are studied and presented. In the first, the proposed vision-based system is employed to let the platform precisely attain its home position. In the second, the platform is referenced to an external coordinate frame, in order to accurately accomplish an assigned task. For both cases, experiments are successfully carried out
Zero-area photons: a brief but intense interaction between light and matter
Facendoli interagire con gli atomi di un gas è possibile modificare profondamente la forma temporale di singoli fotoni e questo potrebbe presto consentire di utilizzarli per trasmettere e memorizzare informazioni in modo molto più sicuro ed efficiente.The temporal shape of single photons can be profoundly altered by making them interact with the atoms of a gas. This could very soon make it possible to use them to transmit and store information in a much more secure and efficient way
Entangling quantum and classical states of light
Entanglement between quantum and classical objects is of special interest in
the context of fundamental studies of quantum mechanics and potential
applications to quantum information processing. In quantum optics, single
photons are treated as light quanta while coherent states are considered the
most classical among all pure states. Recently, entanglement between a single
photon and a coherent state in a free-traveling field was identified to be a
useful resource for optical quantum information processing. However, it was
pointed out to be extremely difficult to generate such states since it requires
a clean cross-Kerr nonlinear interaction. Here, we devise and experimentally
demonstrate a scheme to generate such hybrid entanglement by implementing a
coherent superposition of two distinct quantum operations. The generated states
clearly show entanglement between the two different types of states. Our work
opens a way to generate hybrid entanglement of a larger size and to develop
efficient quantum information processing using such a new type of qubits.Comment: 9 pages, 4 figure
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