In October/December 2021, World Health Organization and other international agencies recommended the offer of third dose anti-SARS-CoV-2 vaccine. this period, routine seasonal influenza vaccination was also guaranteed simultaneous administration two vaccines encouraged. This study aims to evaluate safety profile estimate incidence SARS-CoV-2 breakthrough infections in subjects receiving simultaneously. The population represented by healthcare workers (HCWs) Bari Policlinico General Hospital...

We find an integrable generalization of the BCS model with nonuniform Coulomb and pairing interaction. The Hamiltonian is by construction since it a functional commuting operators; these operators, which therefore are constants motion model, contain anisotropic Gaudin Hamiltonians. exact solution obtained diagonalizing them means Bethe ansatz. Uniform interaction as "isotropic limit" discuss possible applications this to single grain system few interacting grains.

The contribution of the detector dynamics to weak measurement is analyzed. According usual theory [Y. Aharonov, D. Z. Albert, and L. Vaidman, Phys. Rev. Lett. 60, 1351 (1988)] outcome a with preselection postselection can be expressed as real part complex number: value. By accounting for Hamiltonian evolution detector, here we find that there proportional imaginary value measurement. This due coherence probe being essential concept meaningful. As particular example, consider spin component sizable.

A weak measurement consists in coupling a system to probe such way that constructive interference generates large output. So far, only the average output of and its variance were studied. Here, characteristic function for moments is provided. The outputs considered are not limited eigenstates pointer or conjugate variable, so results apply any observable $\Hat{o}$ probe. Furthermore, family well behaved complex quantities, normal values, introduced, terms which statistics can be described....

It is shown how it possible to reconstruct the initial state of a one-dimensional system by measuring sequentially two conjugate variables. The procedure relies on quasi-characteristic function, Fourier-transform Wigner quasi-probability. proper characteristic function obtained Fourier-transforming experimentally accessible joint probability observing "position" then "momentum" (or vice versa) can be expressed as product detectors and that, unknown, quantum system. This allows reconstruction...

We study the spin susceptibility chi of a small, isolated superconducting grain. Because interplay between parity effects and pairing correlations, dependence on temperature T is qualitatively different from standard BCS result valid in bulk limit. If number electrons grain odd, shows re-entrant behavior as function temperature. This persists even case ultrasmall grains where mean level spacing much larger than gap. even, chi(T) exponentially small at low temperatures.

We study the full counting statistics of electric current to several drain terminals with spin-dependent entrance conductances. show that charge transfers can be interpreted in terms single electrons and spin-singlet pairs coming from source. If source contains transport channels high transparency, a significant fraction comes pairs.

We discuss how to detect fluctuating spin currents and derive full counting statistics of electron transfers. consider several detectors in series monitoring different components the spins. have found that general measurement outcomes cannot be explained with projection postulate essentially depends on quantum dynamics detectors.

Heisenberg formulated a noise-disturbance principle stating that there is tradeoff between noise and disturbance when measurement of position momentum are performed sequentially, another imposing limitation on the product uncertainties in joint momentum. We prove former, sequential principle, holds detectors assumed to be initially uncorrelated from each other, but it can violated for some properly correlated initial preparations detectors.

We demonstrate that the task of determining an unknown quantum state can be accomplished efficiently by making a sequential measurement two observables $\hat{A}$ and $\hat{B}$, provided are chosen in such way their eigenstates may form bases connected discrete Fourier transform. The pure or mixed, dimension Hilbert space coupling strength arbitrary, experimental setup is fixed. concept Moyal quasicharacteristic function introduced for finite-dimensional spaces.

It is demonstrated that the statistics for a joint measurement of two conjugate variables in quantum mechanics are expressed through an equation identical to classical one, provided probabilities replaced by Wigner functions and interaction between system detectors accounted for. This constitutes extension Ehrenfest's correspondence principle thereby dubbed strong principle. Furthermore, it proved provide additive term all cumulants if they prepared Gaussian state contribute only first...

A hidden-variable model reproducing the quantum mechanical probabilities for a spin singlet is presented. The violates only hypothesis of independence distribution hidden variables from detector settings and vice versa (measurement independence). It otherwise satisfies hypotheses setting independence, outcome independence—made in derivation Bell inequality—and that compliance with Malus's law—made Leggett inequality. shown violation measurement may be explained alternatively by assuming...

The experimental violation of Bell inequality establishes necessary but not sufficient conditions that any theory must obey. Namely, a compatible with the observations can satisfy at most two three hypotheses basis Bell's theorem: free will, no-signaling, and outcome-Independence. Quantum mechanics satisfies first latter. Experiments only violate inequality, show an excellent agreement quantum mechanics. This fact restricts further class admissible theories. In this work, author determines...

We discuss the full counting statistics (FCS) of noncommuting variables with measurement successive spin counts in noncollinear directions taken as an example. show that owing to irreducible detector back action, FCS this case may be sensitive dynamics detectors, and differ from predictions obtained using a naive version projection postulate. present here general model path-integral approach evaluation FCS. concentrate further on simple ``diffusive'' where can evaluated transfer-matrix...

We analyze the proposal of Aharonov, Popescu, Rohrlich and Skrzypczyk [New. J. Phys. 15, 113015] disembodying physical properties from particles. argue that a different criterion, based on cross-average $\langle \mathrm{`}cat\ somewhere \mbox{'}\times \mathrm{`}grin\ somewhere\ else\mbox{'}\rangle$ should be used to detect disembodiment, rather than local averages \mbox{'}\rangle$ $\langle\mathrm{`}grin\ else\mbox{'}\rangle$. Here, exact probability distribution its characteristic function...

First, a misconception about the spectrum of confined particle is evidentiated. Then, results are shown to be incorrect by means counter-example, an explicit preparation for probe given that yields arbitrary amplification, and source error pointed out.

A measurement consists in coupling a system to probe and reading the output of gather information about system. The weaker coupling, smaller back-action on system, but also less conveyed. If undergoes second measurement, statistics first can be conditioned value one. This procedure is known as postselection. postselected weak an observable give large average when state nearly orthogonal initial interference effect readout probe, which initially coherent superposition states (also pointer...

We show that a single particle in superposition of different paths can entangle two objects located on each path. The entanglement has its maximum visibility for intermediate coupling strengths. In particular, when the quantum systems with which interacts are detectors measure presence and polarization, peculiar situation separated have never mutually interacted is realized.

In a seminal work, Aharonov, Albert, and Vaidman showed that by having weak interaction between system detecting apparatus, the average output of latter could be much larger than maximum eigenvalue observed quantity (times amplification factor). This does not always happen, however: must subsequently undergo second measurement, on which result first one is conditioned. procedure known as postselection. On other hand, linear response theory describes how observables quan- tum change upon...

It is shown that the probabilities for spin singlet can be reproduced through classical resources, with no communication between distant parties, by using merely shared (pseudo-)randomness. If parties are conscious beings aware of both hidden-variables and random mechanism, then one has a conspiracy. only variables, they may induced to believe able send instantaneous information another. also possible reproduce correlations at price reducing detection efficiency. further demonstrated same...