10.9k citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Institute for High Energy PhysicsES2k papers
- Institució Catalana de Recerca i Estudis AvançatsES1.3k papers
- Centre National de la Recherche ScientifiqueFR1.2k papers
- University of PisaIT1.2k papers
- University College LondonGB1.1k papers
- Lawrence Berkeley National LaboratoryUS1.1k papers
- University of MichiganUS1.1k papers
- University of GenevaCH1.1k papers
- The Ohio State UniversityUS1.1k papers
- University of ChicagoUS1k papers
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- Istituto Nazionale di Fisica Nucleare, Sezione di PisaIT1k papers
20 papers · 2 filters
Coherent generation of EPR-entangled light pulses mediated by a single trapped atom
Giovanna Morigi, Jürgen Eschner, Stefano Mancini +1
We show that a single, trapped, laser-driven atom in a high-finesse optical cavity allows for the quantum-coherent generation of entangled light pulses on demand. Schemes for gener…
Separable Measurement Estimation of Density Matrices and its Fidelity Gap with Collective Protocols
E. Bagan, M. A. Ballester, R. D. Gill +2
We show that there exists a gap between the performance of separable and collective measurements in qubit mixed-state estimation that persists in the large sample limit. We charact…
Three level atom optics in dipole traps and waveguides
K. Eckert, J. Mompart, R. Corbalan +2
An analogy is explored between a setup of three atomic traps coupled via tunneling and an internal atomic three-level system interacting with two laser fields. Within this scenario…
Inelastic scattering of light by a cold trapped atom: Effects of the quantum center-of-mass motion
Marc Bienert, Wolfgang Merkel, Giovanna Morigi
The light scattered by a cold trapped ion, which is in the stationary state of laser cooling, presents features due to the mechanical effects of atom-photon interaction. These feat…
Optimal full estimation of qubit mixed states
E. Bagan, M. A. Ballester, R. D. Gill +2
We obtain the optimal scheme for estimating unknown qubit mixed states when an arbitrary number N of identically prepared copies is available. We discuss the case of states in the…
Purity estimation with separable measurements
E. Bagan, M. A. Ballester, R. Munoz-Tapia +1
Given a large number N of copies of a qubit state of which we wish to estimate its purity, we prove that separable-measurement protocols can be as efficient as the optimal joint-me…
Optimal phase measurements with pure Gaussian states
Alex Monras
We analyze the Heisenberg limit on phase estimation for Gaussian states. In the analysis, no reference to a phase operator is made. We prove that the squeezed vacuum state is the m…
Relative states, quantum axes and quantum references
E. Bagan, S. Iblisdir, R. Munoz-Tapia
We address the problem of measuring the relative angle between two "quantum axes" made out of N1 and N2 spins. Closed forms of our fidelity-like figure of merit are obtained for an…
Disordered complex systems using cold gases and trapped ions
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein +3
We report our research on disordered complex systems using cold gases and trapped ions, and address the possibility of using complex systems for quantum information processing. Two…
Mechanical effects of optical resonators on driven trapped atoms: Ground state cooling in a high finesse cavity
Stefano Zippilli, Giovanna Morigi
We investigate theoretically the mechanical effects of light on atoms trapped by an external potential, whose dipole transition couples to the mode of an optical resonator and is d…
Continuous Variable Solution for Byzantine Agreement
Rodion Neigovzen, Anna Sanpera
We demonstrate that the Byzantine Agreement Problem (BAP) in its weaker version with detectable broadcast, can be solved using continuous variables Gaussian states with Gaussian op…
Quantum Information Processing in Disordered and Complex Quantum Systems
Aditi Sen De, Ujjwal Sen, Veronica Ahufinger +3
We investigate quantum information processing and manipulations in disordered systems of ultracold atoms and trapped ions. First, we demonstrate generation of entanglement and loca…
Popper's test of quantum mechanics and two-photon "ghost" diffraction
A. Bramon, R. Escribano
A test on quantum mechanics proposed long ago by Karl Popper is reconsidered with further detail and new insight. An ambiguity in the proposal, which turns out to be essential in o…
Entangled light pulses from single cold atoms
Giovanna Morigi, Juergen Eschner, Stefano Mancini +1
The coherent interaction between a laser-driven single trapped atom and an optical high-finesse resonator allows to produce entangled multi-photon light pulses on demand. The mecha…
Spin gases as microscopic models for non-Markovian decoherence
L. Hartmann, J. Calsamiglia, W. Dür +1
We analyze a microscopic decoherence model in which the total system is described as a spin gas. A spin gas consists of N classically moving particles with additional, interacting…
Measuring the purity of a qubit state: entanglement estimation with fully separable measurements
E. Bagan, M. A. Ballester, R. Munoz-Tapia +1
Given a finite number of copies of a qubit state we compute the maximum fidelity that can be attained using joint-measurement protocols for estimating its purity. We prove that…
Cooling trapped atoms in optical resonators
Stefano Zippilli, Giovanna Morigi
We derive an equation for the cooling dynamics of the quantum motion of an atom trapped by an external potential inside an optical resonator. This equation has broad validity and a…
Aligning Spatial Frames Through Quantum Channels
E. Bagan, R. Munoz-Tapia
We review the optimal protocols for aligning spatial frames using quantum systems. The communication problem addressed here concerns a type of information that cannot be digitalize…
One- and two-dimensional quantum walks in arrays of optical traps
K. Eckert, J. Mompart, G. Birkl +1
We propose a novel implementation of discrete time quantum walks for a neutral atom in an array of optical microtraps or an optical lattice. We analyze a one-dimensional walk in po…
Bell's inequality tests with meson-antimeson pairs
A. Bramon, R. Escribano, G. Garbarino
Recent proposals to test Bell's inequalities with entangled pairs of pseudoscalar mesons are reviewed. This includes pairs of neutral kaons or B-mesons and offers some hope to clos…