Search results for "Quantum imaging"
showing 10 items of 11 documents
Quantum coherence and entanglement with ultracold atoms in optical lattices
2008
At nanokelvin temperatures, ultracold quantum gases can be stored in optical lattices, which are arrays of microscopic trapping potentials formed by laser light. Such large arrays of atoms provide opportunities for investigating quantum coherence and generating large-scale entanglement, ultimately leading to quantum information processing in these artificial crystal structures. These arrays can also function as versatile model systems for the study of strongly interacting many-body systems on a lattice.
High-resolution scanning electron microscopy of an ultracold quantum gas
2008
Our knowledge of ultracold quantum gases is strongly influenced by our ability to probe these objects. In situ imaging combined with single-atom sensitivity is an especially appealing scenario, as it can provide direct information on the structure and the correlations of such systems. For a precise characterization a high spatial resolution is mandatory. In particular, the perspective to study quantum gases in optical lattices makes a resolution well below one micrometre highly desirable. Here, we report on a novel microscopy technique, which is based on scanning electron microscopy and allows for the detection of single atoms inside a quantum gas with a spatial resolution of better than 15…
Ultrafast Fault-Tolerant Long-Distance Quantum Communication with Static Linear Optics
2017
We present an in-depth analysis regarding the error resistance and optimization of our all-optical Bell measurement and ultrafast long-distance quantum communication scheme proposed in [arXiv:1503.06777]. In order to promote our previous proposal from loss- to fault-tolerance, we introduce a general and compact formalism that can also be applied to other related schemes (including non-all-optical ones such as [PRL 112, 250501]). With the help of this new representation we show that our communication protocol does not only counteract the inevitable photon loss during channel transmission, but is also able to resist common experimental errors such as Pauli-type errors (bit- and phase-flips) a…
Adiabatic quantum simulation with a segmented ion trap: Application to long-distance entanglement in quantum spin systems
2013
We investigate theoretically systems of ions in segmented linear Paul traps for the quantum simulation of quantum spin models with tunable interactions. The scheme is entirely general and can be applied to the realization of arbitrary spin-spin interactions. As a specific application we discuss in detail the quantum simulation of models that exhibit long-distance entanglement in the ground state. We show how tailoring of the axial trapping potential allows for generating spin-spin coupling patterns that are suitable to create long-distance entanglement. We discuss how suitable sequences of microwave pulses can implement Trotter expansions and realize various kinds of effective spin-spin int…
Temporal ghost imaging with photon pairs
2017
International audience; We present an experiment of temporal ghost imaging based on the spatial properties of twin photons. The retrieval of a binary time signal of 8 bits is performed with an error rate of 0.70%.
Multidimensional optical sensing and imaging for displays, computational imaging, optical security, and healthcare
2016
In this invited paper, we present an overview of our recently published work on 3D imaging, visualization and displays, including optical security using quantum imaging principles, 3D microscopy, healthcare, automated disease identification with 3D imaging, fatigue free augmented reality 3D glasses, and optical security and authentication using photon counting for IC inspection, polarimetric photon counting 3D imaging, and 3D human gesture recognition
On-chip generation of high-dimensional entangled quantum states and their coherent control
2017
Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science1. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics2, for increasing the sensitivity of quantum imaging schemes3, for improving the robustness and key rate of quantum communication protocols4, for enabling a richer variety of quantum simulations5, and for achieving more efficient and error-tolerant quantum computation6. Integrated photonics has recently become a leading platform for the co…
Practical system for the generation of pulsed quantum frequency combs
2017
The on-chip generation of large and complex optical quantum states will enable low-cost and accessible advances for quantum technologies, such as secure communications and quantum computation. Integrated frequency combs are on-chip light sources with a broad spectrum of evenly-spaced frequency modes, commonly generated by four-wave mixing in optically-excited nonlinear micro-cavities, whose recent use for quantum state generation has provided a solution for scalable and multi-mode quantum light sources. Pulsed quantum frequency combs are of particular interest, since they allow the generation of single-frequency-mode photons, required for scaling state complexity towards, e.g., multi-photon…
Generation of multimode squeezing and entanglement in the space and frequency domains : A general “supermode” approach
2009
Optical parametric oscillators (OPO) have been extensively used in the continuous variable quantum optics community as a resource to produce non-classical states of light, including squeezed states or entangled beams. They have been widely studied, theoretically and experimentally, in the single mode case, and have found many applications to quantum information protocols and high sensitivity optical measurements. However, as the complexity of quantum information protocols increases, the need for multiplexed quantum channels has emerged, which require the use of multimode non-classical states of light.
Quantum fluctuations and coherence in high-precision single-electron capture.
2012
The phase of a single quantum state is undefined unless the history of its creation provides a reference point. Thus quantum interference may seem hardly relevant for the design of deterministic single-electron sources which strive to isolate individual charge carriers quickly and completely. We provide a counterexample by analyzing the non-adiabatic separation of a localized quantum state from a Fermi sea due to a closing tunnel barrier. We identify the relevant energy scales and suggest ways to separate the contributions of quantum non-adiabatic excitation and backtunneling to the rare non-capture events. In the optimal regime of balanced decay and non-adiabaticity, our simple electron tr…