Interference of spin-orbit coupled Bose-Einstein condensates

Interference of atomic Bose-Einstein condensates, observed in free expansion experiments, is a basic characteristic of their quantum nature. The ability to produce synthetic spin-orbit coupling in Bose-Einstein condensates has recently opened a new research field. Here we theoretically describe interference of two noninteracting spin-orbit coupled Bose-Einstein condensates in an external synthetic magnetic field. We demonstrate that the spin-orbit and the Zeeman couplings strongly influence the interference pattern determined by the angle between the spins of the condensates, as can be seen in time-of-flight experiments. We show that a quantum backflow, being a subtle feature of the interference, is, nevertheless, robust against the spin-orbit coupling and applied synthetic magnetic field.Comment: published versio

Editorial

[EN] They allow readers to understand how, through the word and the legacy of inhabitants, through educational experiences and outreach activities, architectural technology in rural areas host a wealthy folk heritage that today is valued as a sustainable resource; as much by the use of materials as by the form of being executed.Palmero, LM. (2020). Editorial. VITRUVIO - International Journal of Architectural Technology and Sustainability. 5(1):VII-VIII. https://doi.org/10.4995/vitruvio-ijats.2020.13758OJSVIIVIII5

Fast bias inversion of a double well without residual particle excitation

We design fast bias inversions of an asymmetric double well so that the lowest states in each well remain so and free from residual motional excitation. This cannot be done adiabatically, and a sudden bias switch produces in general motional excitation. The residual excitation is suppressed by complementing a predetermined fast bias change with a linear ramp whose time-dependent slope compensates for the displacement of the wells. The process, combined with vibrational multiplexing and demultiplexing, can produce vibrational state inversion without exciting internal states, just by deforming the trap.Comment: 7 pages, 6 figure

Shortcuts to adiabaticity for an ion in a rotating radially-tight trap

We engineer the fast rotation of a quantum particle confined in an effectively one-dimensional, harmonic trap, for a predetermined rotation angle and time, avoiding final excitation. Different schemes are proposed with different speed limits that depend on the control capabilities. We also make use of trap rotations to create squeezed states without manipulating the trap frequencies.Comment: 11 pages, 6 figure

The relationship between Mathematical Utility Theory and the Integrability Problem: some arguments in favour

The resort to utility-theoretical issues will permit us to propose a constructive procedure for deriving a homogeneous of degree one, continuous function that gives raise to a primitive demand function under suitably mild conditions. This constitutes the first elementary proof of a necessary and sufficient condition for an integrability problem to have a solution by continuous (subjective utility) functions. Such achievement reinforces the relevance of a technique that was succesfully formalized in Alcantud and Rodríguez-Palmero (2001). The analysis of these two works exposes deep relationships between two apparently separate fields: mathematical utility theory and the revealed preference approach to the integrability problem.Strong Axiom of Homothetic Revelation; revealed preference; continuous homogeneous of degree one utility; integrability of demand.

Alkali-activation of aggregate fines from construction and demolition waste: valorisation in view of road pavement subbase applications

This study investigates the potential of fine particles of recycled construction and demolition waste (CDW) aggregate to undergo alkali-activation when mixed with an appropriate alkaline solution. The fine is a natural by-product of the milling process and includes particles from four main material sources (i.e., recycled concrete, recycled asphalt, crushed bricks and tiles, and natural aggregate and excavated soil) and other occasional elements which are too small for identification. The fine was obtained by sifting the material through a 125 μm sieve. Since the reactivity of unselected material depends on its constituents, these were also individually investigated. Firstly, the four constituents of CDW recycled aggregates were separated, then milled to a size smaller than 125 μm, before being tested to measure their reactivity to an alkaline solution. A preliminary chemical and mineralogical characterization of the five powders was carried out to identify the main crystalline phases and ascertain the presence of aluminosilicates needed for the alkali activation process. Particles of each powder were afterwards mixed with three concentrations of the same alkaline solution with a liquid/solid mass ratio of 0.4, cast in prismatic moulds, and cured at room temperature. Mechanical tests after 3, 7, and 28 days of curing demonstrated that powders react positively in a basic environment, showing an increase in strength without any thermal treatment. Hardened pastes of undivided fine aggregate and recycled asphalt exhibited the best results in terms of flexural and compressive strength with the more concentrated solution. A Field Emission Scanning Electron Microscopy analysis was also carried out to observe the microstructure and to support an interpretation of the mechanical strength data. Results demonstrated the feasibility of using a solution to activate unselected CDW fine particles to stabilize CDW aggregates. In full scale applications, CDW aggregates can be stabilized without the addition of any binder