Understanding the great trade collapse of 2008–09 and the subsequent trade recovery

This article documents the Great Trade Collapse of 2008–09, as well as the dramatic recovery in trade of 2009–10. The authors consider how three distinct policy actions — fiscal stimulus, funding for trade finance and a commitment to refrain from increasing trade barriers — might have affected both the collapse and recovery.Gross domestic product ; Trade ; Recessions

Spin-tensor--momentum-coupled Bose-Einstein condensates

The recent experimental realization of spin-orbit coupling for ultracold atomic gases provides a powerful platform for exploring many interesting quantum phenomena. In these studies, spin represents spin vector (spin-1/2 or spin-1) and orbit represents linear momentum. Here we propose a scheme to realize a new type of spin-tensor--momentum coupling (STMC) in spin-1 ultracold atomic gases. We study the ground state properties of interacting Bose-Einstein condensates (BECs) with STMC and find interesting new types of stripe superfluid phases and multicritical points for phase transitions. Furthermore, STMC makes it possible to study quantum states with dynamical stripe orders that display density modulation with a long tunable period and high visibility, paving the way for direct experimental observation of a new dynamical supersolid-like state.. Our scheme for generating STMC can be generalized to other systems and may open the door for exploring novel quantum physics and device applications.Comment: 6 pages, 4 figures (main text) + 5 pages (Supplementary Materials), typos corrected, final versio