Extracting kinetic information from short-time trajectories: relaxation and disorder of lossy cavity polaritons.

The emerging field of molecular cavity polaritons has stimulated a surge of experimental and theoretical activities and presents a unique opportunity to develop the many-body simulation methodology. This paper presents a numerical scheme for the extraction of key kinetic information of lossy cavity polaritons based on the transfer tensor method (TTM). Steady state, relaxation timescales, and oscillatory phenomena can all be deduced directly from a set of transfer tensors without the need for long-time simulation.

Highly Dispersed Pd@ZIF-8 for Photo-Assisted Cross-Couplings and CO to Methanol: Activity and Selectivity Insights.

Our study unveils a pioneering methodology that effectively distributes Pd species within a zeolitic imidazolate framework-8 (ZIF-8). We demonstrate that Pd can be encapsulated within ZIF-8 as atomically dispersed Pd species that function as an excited-state transition metal catalyst for promoting carbon-carbon (C-C) cross-couplings at room temperature using visible light as the driving force. Furthermore, the same material can be reduced at 250 °C, forming Pd metal nanoparticles encapsulated in ZIF-8.

Low frequency signal detection via correlated Ramsey measurements.

The low frequency region of the spectrum is a challenging regime for quantum probes. We support the idea that, in this regime, performing Ramsey measurements carefully controlling the time at which each measurement is initiated is an excellent signal detection strategy. We use the Fisher information to demonstrate a high quality performance in the low frequency regime, compared to more elaborated measurement sequences, and to optimize the correlated Ramsey sequence according to any given experimental parameters, showing that correlated Ramsey rivals with state-of-the-art protocols, and can even outperform commonly employed sequences such as dynamical decoupling in the detection of low frequency signals.

Copper nanoparticles encapsulated in zeolitic imidazolate framework-8 as a stable and selective CO hydrogenation catalyst.

Metal-organic frameworks have drawn attention as potential catalysts owing to their unique tunable surface chemistry and accessibility. However, their application in thermal catalysis has been limited because of their instability under harsh temperatures and pressures, such as the hydrogenation of CO to methanol. Herein, we use a controlled two-step method to synthesize finely dispersed Cu on a zeolitic imidazolate framework-8 (ZIF-8).

Highly Efficient and Stable Methane Dry Reforming Enabled by a Single-Site Cationic Ni Catalyst.

Zeolite-supported nickel (Ni) catalysts have been extensively studied for the dry reforming of methane (DRM). It is generally believed that prior to or during the reaction, Ni is reduced to a metallic state to act as the catalytic site. Here, we employed a ligand-protected synthesis method to achieve a high degree of Ni incorporation into the framework of the MFI zeolite.

Zeolite Synthesis in the Presence of Metallosiloxanes for the Quantitative Encapsulation of Metal Species for the Selective Catalytic Reduction (SCR) of NO.

Metal encapsulation in zeolitic materials through one-pot hydrothermal synthesis (HTS) is an attractive technique to prepare zeolites with a high metal dispersion. Due to its simplicity and the excellent catalytic performance observed for several catalytic systems, this method has gained a great deal of attention over the last few years. While most studies apply synthetic methods involving different organic ligands to stabilize the metal under synthesis conditions, here we report the use of metallosiloxanes as an alternative metal precursor.

A frequency comb stabilized Ti:Sa laser as a self-reference for ion-trap experiments with a Ca ion.

In this study, we report on the stabilization of a continuous-wave Ti:Sa laser to an optical frequency comb. The laser is emitting at 866 nm to address one of the transitions required for Doppler cooling of a single Ca ion in a linear Paul trap (D ↔P1/22). The stabilized Ti:Sa laser is utilized to calibrate an ultra-accurate wavelength meter.

Modifying the Hydrogenation Activity of Zeolite Beta for Enhancing the Yield and Selectivity for Fuel-Range Alkanes from Carbon Dioxide.

In order to empower a circular carbon economy for addressing global CO emissions, the production of carbon-neutral fuels is especially desired, since addressing the global fuel demand via this route has the potential to significantly mitigate carbon emissions. In this study, we report a multifunctional catalyst combination consisting of a potassium promoted iron catalyst (Fe-K) and platinum containing zeolite beta (Pt-beta) which produces an almost entirely paraffinic mixture (up to C hydrocarbons) via CO hydrogenation in one step. Here, the Fe catalyst is responsible for modified Fischer-Tropsch synthesis from CO while Pt-beta is instrumental in tuning the product distribution almost entirely towards paraffins (both linear and branched) presumably via a combination of cracking and hydrogenation.

Fundamentals and applications of photo-thermal catalysis.

Correction for 'Fundamentals and applications of photo-thermal catalysis' by Diego Mateo , , 2021, , 2173-2210, DOI: 10.1039/D0CS00357C.

Designing a Multifunctional Catalyst for the Direct Production of Gasoline-Range Isoparaffins from CO.

The production of carbon-neutral fuels from CO presents an avenue for causing an appreciable effect in terms of volume toward the mitigation of global carbon emissions. To that end, the production of isoparaffin-rich fuels is highly desirable. Here, we demonstrate the potential of a multifunctional catalyst combination, consisting of a methanol producer (InCo) and a Zn-modified zeolite beta, which produces a mostly isoparaffinic hydrocarbon mixture from CO (up to ∼85% isoparaffin selectivity among hydrocarbons) at a CO conversion of >15%.

Coherent manipulation of an Andreev spin qubit.

Two promising architectures for solid-state quantum information processing are based on electron spins electrostatically confined in semiconductor quantum dots and the collective electrodynamic modes of superconducting circuits. Superconducting electrodynamic qubits involve macroscopic numbers of electrons and offer the advantage of larger coupling, whereas semiconductor spin qubits involve individual electrons trapped in microscopic volumes but are more difficult to link. We combined beneficial aspects of both platforms in the Andreev spin qubit: the spin degree of freedom of an electronic quasiparticle trapped in the supercurrent-carrying Andreev levels of a Josephson semiconductor nanowire.

Low Field Nano-NMR via Three-Level System Control.

Conventional control strategies for nitrogen-vacancy centers in quantum sensing are based on a two-level model of their triplet ground state. However, this approach fails in regimes of weak bias magnetic fields or strong microwave pulses, as we demonstrate. To overcome this limitation, we propose a novel control sequence that exploits all three levels by addressing a hidden Raman configuration with microwave pulses tuned to the zero-field transition.

Fundamentals and applications of photo-thermal catalysis.

Photo-thermal catalysis has recently emerged as an alternative route to drive chemical reactions using light as an energy source. Through the synergistic combination of photo- and thermo-chemical contributions of sunlight, photo-thermal catalysis has the potential to enhance reaction rates and to change selectivity patterns, even under moderate operation conditions. This review provides the fundamentals of localized surface plasmon resonance (LSPR) that explain the photo-thermal effect in plasmonic structures, describes the different mechanistic pathways underlying photo-thermal catalysis, suggests methodologies to disentangle the reaction mechanisms and proposes material design strategies to improve photo-thermal performance.

An in situ XAS study of the activation of precursor-dependent Pd nanoparticles.

The activation of precursor-dependent Pd nanoparticles was comprehensively followed by in situ X-ray absorption spectroscopy on two inorganic supports for rationalizing the final catalytic activity. Two series of Pd-based catalysts (7 wt% Pd) were prepared by impregnation of γ-Al2O3 and activated carbon supports varying the metal precursor (Pd(NO3)2, PdCl2 and Pd(OAc)2). The most relevant physicochemical properties of the studied catalysts were determined by several techniques including ICP-OES, XRD, N2 adsorption and XAS.

Publisher's Note: Driven Open Quantum Systems and Floquet Stroboscopic Dynamics [Phys. Rev. Lett. 117, 250401 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.117.

Driven Open Quantum Systems and Floquet Stroboscopic Dynamics.

We provide an analytic solution to the problem of system-bath dynamics under the effect of high-frequency driving that has applications in a large class of settings, such as driven-dissipative many-body systems. Our method relies on discrete symmetries of the system-bath Hamiltonian and provides the time evolution operator of the full system, including bath degrees of freedom, without weak-coupling or Markovian assumptions. An interpretation of the solution in terms of the stroboscopic evolution of a family of observables under the influence of an effective static Hamiltonian is proposed, which constitutes a flexible simulation procedure of nontrivial Hamiltonians.

Thermodynamics of stochastic Turing machines.

In analogy to Brownian computers we explicitly show how to construct stochastic models which mimic the behavior of a general-purpose computer (a Turing machine). Our models are discrete state systems obeying a Markovian master equation, which are logically reversible and have a well-defined and consistent thermodynamic interpretation. The resulting master equation, which describes a simple one-step process on an enormously large state space, allows us to thoroughly investigate the thermodynamics of computation for this situation.

Non-Markovian dynamical maps: numerical processing of open quantum trajectories.

The initial stages of the evolution of an open quantum system encode the key information of its underlying dynamical correlations, which in turn can predict the trajectory at later stages. We propose a general approach based on non-Markovian dynamical maps to extract this information from the initial trajectories and compress it into non-Markovian transfer tensors. Assuming time-translational invariance, the tensors can be used to accurately and efficiently propagate the state of the system to arbitrarily long time scales.

Pulsed laser cooling for cavity optomechanical resonators.

A pulsed cooling scheme for optomechanical systems is presented that is capable of cooling at much faster rates, shorter overall cooling times, and for a wider set of experimental scenarios than is possible by conventional methods. The proposed scheme can be implemented for both strongly and weakly coupled optomechanical systems in both weakly and highly dissipative cavities. We study analytically its underlying working mechanism, which is based on interferometric control of optomechanical interactions, and we demonstrate its efficiency with pulse sequences that are obtained by using methods from optimal control.

[Analysis of results, quality indicators, and postsurgical complications in an outpatient dermatological surgery program].

Objective: To evaluate the results of an outpatient program for major dermatological surgery in patients with a range of skin conditions.

Methods: We undertook a retrospective, observational study of patients who underwent scheduled dermatological surgery as outpatients in a public hospital between 2004 and 2007. The most common procedures were excision of basal cell or squamous cell carcinoma with or without graft reconstruction.

Fast and robust laser cooling of trapped systems.

We present a robust and fast laser cooling scheme suitable for trapped ions, atoms, or cantilevers. Based on quantum interference, generated by a special laser configuration, it is able to rapidly cool the system such that the final phonon occupation vanishes to zeroth order in the Lamb-Dicke parameter in contrast to existing cooling schemes. Furthermore, it is robust under conditions of fluctuating laser intensity and frequency, thus making it a viable candidate for experimental applications.