About QUINST

Quantum mechanics is at the heart of our technology and economy - the laser and the transistor are quantum devices - but its full potential is far from being realized. Recent technological advances in optics, nanoscience and engineering allow experimentalists to create artificial structures or put microscopic and mesoscopic systems under new manipulable conditions in which quantum phenomena play a fundamental role.

Quantum technologies exploit these effects with practical purposes. The objective of Quantum Science is to discover, study, and control quantum efects at a fundamental level. These are two sides of a virtuous circle: new technologies lead to the discovery and study of new phenomena that will lead to new technologies.

Our aim is  to control and understand quantum phenomena in a multidisciplinary intersection of  Quantum Information, Quantum optics and cold atoms, Quantum Control, Spintronics, Quantum metrology, Atom interferometry, Superconducting qubits and Circuit QED and Foundations of Quantum Mechanics.

QUINST is funded in part as a “Grupo Consolidado” from the Basque Government (IT472-10, IT986-16, IT1470-22)  and functions as a network of groups with their own funding, structure, and specific goals.  

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Prof. Boris Malomed (Tel Aviv University) (Seminar)

When and where

From: 10/08/2016 To: 10/02/2016

Description

October 20, 12.00, Salon de Grados

Dear colleagues:

I am pleased to welcome you to seminar of Prof. Boris Malomed
(Tel Aviv University) on Tuesday, October 20.

 

Title: Stable two-dimensional solitons in spin-orbit-coupled self-attractive Bose-Einstein condensates

 

Abstract

It is commonly known that two-dimensional mean-field models of optical and matter waves with cubic self-attraction cannot produce stable solitons in free space because of the occurrence of collapse in the same setting. By means of numerical analysis and variational approximation, we demonstrate that the two-component model of the Bose-Einstein condensate with the Rashba spin-orbit coupling (SOC) and cubic attractive interactions gives rise to stable solitary-vortex complexes of two types in the free space: semivortices  (SVs, with a vortex in one component and a fundamental soliton in the other), and mixed modes (MMs, with topological charges 0 and ±1 mixed in both components). The SVs and MMs realize the ground state of the system, provided that the self-attraction in the two components is, respectively, stronger or weaker than the cross attraction between them. The SVs and MMs which are not the ground states are subject to a drift instability. Moving free-space stable solitons are also found in the present non-Galilean-invariant system.

 

Additional results demonstrate similar solitons in the  one-dimensional and discrete two-dimensional versions of the SOC system.

 

The work was recently published in:

H. Sakaguchi, B. Li, and B. A. Malomed, "Creation of two-dimensional composite solitons in spin-orbit-coupled self-attractive Bose-Einstein condensates in free space", Phys. Rev. E 89, 032920 (2014);


H. Sakaguchi and B. A. Malomed, "Discrete and continuum composite solitons in Bose-Einstein condensates with the Rashba spin-orbit coupling in one and two dimensions", Phys. Rev. E 90, 062922 (2014).