ICFO – The Institute of Photonic Sciences

About: ICFO – The Institute of Photonic Sciences is a facility organization based out in Barcelona, Spain. It is known for research contribution in the topics: Quantum & Quantum entanglement. The organization has 872 authors who have published 1965 publications receiving 56273 citations.

Correlation measure detecting almost all non-Markovian evolutions

Abstract: We investigate the ability of correlation measures to witness non-Markovian open-quantum-system dynamics. It is shown that the mutual information and any entanglement measure between the system and an ancilla do not witness all non-Markovian dynamics. A correlation measure is introduced, and it is proven that, in an enlarged setting with two ancillary systems, this measure detects almost all non-Markovian dynamics, except possibly a zero-measure set of dynamics that is nonbijective in finite time intervals. Our proof is constructive and provides different initial states detecting the non-Markovian evolutions. These states are all separable and some are arbitrarily close to a product state. A further advantage of the introduced correlation measure is that it can be efficiently computed through semidefinite programming.

Ultracold magnetically tunable interactions without radiative-charge-transfer losses between Ca + , Sr + , Ba + , and Yb + ions and Cr atoms

Abstract: The ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$, and ${\mathrm{Yb}}^{+}$ ions immersed in an ultracold gas of the Cr atoms are proposed as experimentally feasible heteronuclear systems in which ion-atom interactions at ultralow temperatures can be controlled with magnetically tunable Feshbach resonances without charge transfer and radiative losses. Ab initio techniques are applied to investigate electronic-ground-state properties of the (CaCr)${}^{+}$, (SrCr)${}^{+}$, (BaCr)${}^{+}$, and (YbCr)${}^{+}$ molecular ions. The potential energy curves, permanent electric dipole moments, and static electric dipole polarizabilities are computed. The spin-restricted open-shell coupled-cluster method restricted to single, double, and noniterative triple excitations and the multireference configuration-interaction method restricted to single and double excitations are employed. The scalar relativistic effects are included within the small-core energy-consistent pseudopotentials. The leading long-range induction and dispersion interaction coefficients are also reported. Finally, magnetic Feshbach resonances between the ${\mathrm{Ca}}^{+}, {\mathrm{Sr}}^{+}, {\mathrm{Ba}}^{+}$, and ${\mathrm{Yb}}^{+}$ ions interacting with the Cr atoms are analyzed. The present proposal opens the way towards robust quantum simulations and computations with ultracold ion-atom systems free of radiative charge-transfer losses.

Neutral Water Splitting Catalysis with a High FF Triple Junction Polymer Cell

Abstract: We report a photovoltaics-electrochemical (PV-EC) assembly based on a compact and easily processable triple homojunction polymer cell with high fill factor (76%), optimized conversion efficiencies up to 8.7%, and enough potential for the energetically demanding water splitting reaction (Voc = 2.1 V). A platinum-free cathode made of abundant materials is coupled to a ruthenium oxide on glassy carbon anode (GC-RuO2) to perform the reaction at optimum potential (ΔE = 1.70–1.78 V, overpotential = 470–550 mV). The GC-RuO2 anode contains a single monolayer of catalyst corresponding to a superficial concentration (Γ) of 0.15 nmol cm—2 and is highly active at pH 7. The PV-EC cell achieves solar to hydrogen conversion efficiencies (STH) ranging from 5.6 to 6.0%. As a result of the solar cell’s high fill factor, the optimal photovoltaic response is found at 1.70 V, the minimum potential at which the electrodes used perform the water splitting reaction. This allows generating hydrogen at efficiencies that would be v...

From the Jaynes-Cummings model to non-abelian gauge theories: a guided tour for the quantum engineer

Abstract: The design of quantum many body systems, which have to fulfill an extensive number of constraints, appears as a formidable challenge within the field of quantum simulation. Lattice gauge theories are a particular important class of quantum systems with an extensive number of local constraints and play a central role in high energy physics, condensed matter and quantum information. Whereas recent experimental progress points towards the feasibility of large-scale quantum simulation of Abelian gauge theories, the quantum simulation of non-Abelian gauge theories appears still elusive. In this paper we present minimal non-Abelian lattice gauge theories, whereby we introduce the necessary formalism in well-known Abelian gauge theories, such as the Jaynes-Cumming model. In particular, we show that certain minimal non-Abelian lattice gauge theories can be mapped to three or four level systems, for which the design of a quantum simulator is standard with current technologies. Further we give an upper bound for the Hilbert space dimension of a one dimensional SU(2) lattice gauge theory, and argue that the implementation with current digital quantum computer appears feasible.

An atomic force microscope operating at hypergravity for in situ measurement of cellular mechano-response.

Abstract: We present a novel atomic force microscope (AFM) system, operational in liquid at variable gravity, dedicated to image cell shape changes of cells in vitro under hypergravity conditions. The hypergravity AFM is realized by mounting a stand-alone AFM into a large-diameter centrifuge. The balance between mechanical forces, both intra- and extracellular, determines both cell shape and integrity. Gravity seems to be an insignificant force at the level of a single cell, in contrast to the effect of gravity on a complete (multicellular) organism, where for instance bones and muscles are highly unloaded under near weightless (microgravity) conditions. However, past space flights and ground based cell biological studies, under both hypogravity and hypergravity conditions have shown changes in cell behaviour (signal transduction), cell architecture (cytoskeleton) and proliferation. Thus the role of direct or indirect gravity effects at the level of cells has remained unclear. Here we aim to address the role of gravity on cell shape. We concentrate on the validation of the novel AFM for use under hypergravity conditions. We find indications that a single cell exposed to 2 to 3 × g reduces some 30–50% in average height, as monitored with AFM. Indeed, in situ measurements of the effects of changing gravitational load on cell shape are well feasible by means of AFM in liquid. The combination provides a promising technique to measure, online, the temporal characteristics of the cellular mechano-response during exposure to inertial forces.