Super revivals and sub-Planck scale structures of a slightly relativistic particle in a box

The time evolution of a particle, caught in an infinitely deep square well, displays unexpected features, when one includes tiny relativistic effects. Indeed, even the smallest corrections to the non-relativistic quadratic spectrum manifest themselves in a dramatic way. Our theoretical analysis brings to light a completely new time scale, at which the system exhibits surprisingly perfect revivals. This longer time scale rules the system dynamics and replaces the original revival time of the unperturbed system. The early manifestation of such phenomenon is captured by the sensitivity of sub-Planck structures for different values of the relativistic corrections.Comment: 13 pages, 4 figures, Accepted in Int. J. Quantum Informatio

From a single- to a double-well Penning trap

The new generation of planar Penning traps promises to be a flexible and versatile tool for quantum information studies. Here, we propose a fully controllable and reversible way to change the typical trapping harmonic potential into a double-well potential, in the axial direction. In this configuration a trapped particle can perform coherent oscillations between the two wells. The tunneling rate, which depends on the barrier height and width, can be adjusted at will by varying the potential difference applied to the trap electrodes. Most notably, tunneling rates in the range of kHz are achievable even with a trap size of the order of 100 microns.Comment: 4 pages, 7 figure

Spin chains with electrons in Penning traps

We demonstrate that spin chains are experimentally feasible using electrons confined in micro-Penning traps, supplemented with local magnetic field gradients. The resulting Heisenberg-like system is characterized by coupling strengths showing a dipolar decay. These spin chains can be used as a channel for short distance quantum communication. Our scheme offers high accuracy in reproducing an effective spin chain with relatively large transmission rate.Comment: 21 pages, 1 figure, accepted for publication in PR

Formation and evolution of a metasomatized lithospheric root at the motionless Antarctic plate: the case of East Island, Crozet Archipelago (Indian Ocean)

Sitting atop the nearly stagnant Antarctic plate (ca. 6.46 mm/yr), the Crozet archipelago midway between Madagascar and Antarctica constitutes a region of unusually shallow (1543-1756 m below sea level) and thickened oceanic crust (10-16.5 km), high geoid height, and deep low-velocity zone, which may reflect the surface expression of a mantle plume. Here, we present new major and trace element data for Quaternary sub-aerial alkali basalts from East Island, the easterly and oldest island (ca. 9 Ma) of the Crozet archipelago. Crystallization at uppermost mantle depth and phenocryst accumulation have strongly affected their parental magma compositions. Their trace element patterns show a large negative K anomaly relative to Ta-La, moderate depletions in Rb and Ba with respect to Th-U, and heavy rare earth element (HREE) depletions relative to light REE. These characteristics allow limits to be placed upon the composition and mineralogy of their mantle source. The average trace element spectrum of East Island basalts can be matched by melting of about 2 % of a garnet-phlogopite-bearing peridotite source. The stability field of phlogopite restricts melting depth to lithospheric levels. The modelled source composition requires a multistage evolution, where the mantle has been depleted by melt extraction before having been metasomatized by alkali-rich plume melts. The depleted mantle component may be sourced by residual mantle plume remnants stagnated at the melting locus due to a weak lateral flow velocity inside the melting regime, whose accumulation progressively edifies a depleted lithospheric root above the plume core. Low-degree alkali-rich melts are likely derived from the plume source. Such a mantle source evolution may be general to both terrestrial and extraterrestrial environments where the lateral component velocity of the mantle flow field is extremely slow

La biblioteca scolastica e il rendimento degli studenti: una relazione da approfondire

This study investigates the relationship between School Library and Students’ achievement on a population sample of 9896 Schools. Many international researches confirmed the importance of the School Library for the Students learning. Recently the IEA PIRLS survey has revealed a positive relationship between the Reading comprehension performance and the size of the School Library collection. In this paper, we verify the relation between the results of INVALSI tests in Italian and Mathematics - on school grades 5,8,10 - with the presence and functioning of the School Library. The information on the School Library comes from the School Questionnaire compiled by the School Principal in the course of the Self-evaluation Report. The analysis confirm a positive relationship in each school grade and in both subjects of investigation

School library and students' achievement: a relationship to go into

This study investigates the relationship between School Library and Students’ achievement on a population sample of 9896 Schools. Many international researches confirmed the importance of the School Library for the Students learning. Recently the IEA PIRLS survey has revealed a positive relationship between the Reading comprehension performance and the size of the School Library collection. In this paper, we verify the relation between the results of INVALSI tests in Italian and Mathematics - on school grades 5,8,10 - with the presence and functioning of the School Library. The information on the School Library comes from the School Questionnaire compiled by the School Principal in the course of the Self-evaluation Report. The analysis confirm a positive relationship in each school grade and in both subjects of investigation

School library and students' achievement: a relationship to go into

This study investigates the relationship between School Library and Students’ achievement on a population sample of 9896 Schools. Many international researches confirmed the importance of the School Library for the Students learning. Recently the IEA PIRLS survey has revealed a positive relationship between the Reading comprehension performance and the size of the School Library collection. In this paper, we verify the relation between the results of INVALSI tests in Italian and Mathematics - on school grades 5,8,10 - with the presence and functioning of the School Library. The information on the School Library comes from the School Questionnaire compiled by the School Principal in the course of the Self-evaluation Report. The analysis confirm a positive relationship in each school grade and in both subjects of investigation

School library and students' achievement: a relationship to go into

This study investigates the relationship between School Library and Students’ achievement on a population sample of 9896 Schools. Many international researches confirmed the importance of the School Library for the Students learning. Recently the IEA PIRLS survey has revealed a positive relationship between the Reading comprehension performance and the size of the School Library collection. In this paper, we verify the relation between the results of INVALSI tests in Italian and Mathematics - on school grades 5,8,10 - with the presence and functioning of the School Library. The information on the School Library comes from the School Questionnaire compiled by the School Principal in the course of the Self-evaluation Report. The analysis confirm a positive relationship in each school grade and in both subjects of investigation

School library and students' achievement: a relationship to go into

This study investigates the relationship between School Library and Students’ achievement on a population sample of 9896 Schools. Many international researches confirmed the importance of the School Library for the Students learning. Recently the IEA PIRLS survey has revealed a positive relationship between the Reading comprehension performance and the size of the School Library collection. In this paper, we verify the relation between the results of INVALSI tests in Italian and Mathematics - on school grades 5,8,10 - with the presence and functioning of the School Library. The information on the School Library comes from the School Questionnaire compiled by the School Principal in the course of the Self-evaluation Report. The analysis confirm a positive relationship in each school grade and in both subjects of investigation