Irene Marzoli

Quantum carpets, carpets of light

In 1836 Henry Fox Talbot, an inventor of photography, published the results of some experiments in optics that he had previously demonstrated at a British Association meeting in Bristol (figure 1a). It was very curious to observe that though the grating was greatly out of the focus of the lens...the appearance of the bands was perfectly distinct and well defined...the experiments are communicated in the hope that they may prove interesting to the cultivators of optical science.

Quantum carpets woven by Wigner functions

The dynamics of many different quantum systems is characterized by a regular net of minima and maxima of probability stretching out in a spacetime representation. We offer an explanation to this phenomenon in terms of the Wigner function. This approach illustrates very clearly the crucial role played by interference.

Quantum spin models with electrons in Penning traps

We propose a scheme to engineer an effective spin Hamiltonian starting from a system of electrons confined in micro-Penning-traps. By means of appropriate sequences of electromagnetic pulses, alternated with periods of free evolution, we control the shape and strength of the spin-spin interaction. Moreover, we can modify the effective magnetic field experienced by the particle spin. This procedure enables us to reproduce notable quantum spin systems, such as Ising and

Three-qubit network with a single trapped electron

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Quantum images in nonlinear optics

models. Thanks to its scalability, our scheme can be applied to a fairly large number of trapped particles within the reach of near future technology.

Quantum carpets: a tool to observe decoherence

We show how a single trapped electron offers the opportunity to realize a universal three-qubit network within the present experimental possibilities. This is achieved by encoding quantum information in the energy states of the cyclotron and spin motions. Furthermore we give the prescriptions to implement the Deutsch-Jozsa algorithm, the Grover algorithm and the quantum Fourier transform.

Investigating Science Teachers’ Transformations of Inquiry Aspects When Implementing Research-Based Teaching-Learning Sequences

Abstract We illustrate the concept of quantum image in the context of degenerate parametric oscillators. In the case of a cavity with planar mirrors, we show the gradual transformation of a quantum image into a classical image as the threshold region is scanned. Thus the quantum image behaves as a precursor of the roll pattern which appears above threshold. In the far field, the configuration of the spatial correlation function of the intensity and of the quadrature components shows unambiguously the quantum nature of fluctuations that generate the quantum image, leading to effects of quantum noise reduction below the shot noise level, and to the formulation of an Einstein–Podolsky–Rosen paradox.

Non-dissipative decoherence for quantum carpets

Quantum carpets—the spatio-temporal de Broglie density profiles—woven by an atom or an electron in the near-field region of a diffraction grating bring to light, in real time, the decoherence of each individual component of the interference term of the Wigner function characteristic of superposition states. The proposed experiments are feasible with present-day technology.

Scalable Quantum Processor with Trapped Electrons

In this study we aimed to investigate the most transformed/accepted aspects of scientific inquiry when it is implemented in classroom practice. Thirteen secondary school teachers participated in the study. The teachers were first involved in a professional development (PD) course aimed at familiarizing them with inquiry principles, using seven teaching-learning sequences (TLSs) as training contexts. Then, teachers implemented one TLS in their classrooms for at least 5 h. A knowledge transfer framework, Adaption and Re-Invention Model, was used to investigate teachers’ transfer of TLS in classroom practice. In particular, core and non-core elements of the TLSs were identified: core elements are essential features of inquiry teaching that should not be changed while implementing a TLS since they characterize it in a unique way. Non-core elements concern classroom management and activities timing and can be changed to fit the TLS into the specific educational context. Collected data have been audio/video recordings. Results show that most accepted aspects of inquiry teaching are related to data collection, support to students, activities timing, and homework tasks. Moreover, most teachers acted as resource persons and valued classroom discussions. Overall, our findings may usefully inform PD courses by providing evidence of teachers’ enactment of inquiry in their practice.

SPATIAL QUANTUM SIGNATURES IN PARAMETRIC DOWN-CONVERSION

Abstract We describe decoherence for quantum carpets using a modelindependent formalism ruled by a characteristic time τ. We find that the rate of decoherence depends critically on the ratio between τ and τE = h/2σH. When τ/τE « 1 decoherence is very slow, while it becomes very fast for the opposite case. The rate of decoherence is described in terms of the fidelity function.