Multi-component states for trapped spin-1 Bose-Einstein Condensates in the presence of magnetic field

In presence of a magnetic field, the multi-component ground states appear for trapped spin-1 Bose-Einstein condensates for both ferromagnetic and anti-ferromagnetic types of spin-spin interaction. We aim to produce an accurate analytical description of the multi-component states which is of fundamental importance. Despite being in the so-called regime of Thomas-Fermi approximation (condensates with large particle number), the scenario of multi-component states is problematic under this approximation due to large variation in densities of the sub-components. We generalize the variational method that we have introduced in the article [Eur. Phys. J. Plus 137, 547 (2022)] to overcome this limitation of T-F approximation. We demonstrate that, the variational method is crucial in giving a proper analytical description of the multi-component states. The results obtained from the variational method are also backed by numerical simulation. A comparison of the strength of our variational method, which is multi-modal, with that of single-mode approximation is also presented in this paper to demonstrate a marked improvement in accuracy over single-mode approximation.Comment: 14 pages, 9 figure

A variational approach for the ground state profile of a trapped spinor-BEC: A detailed study of phase transition in spin-1 condensate at zero magnetic field

The ground state of a spin-1 Bose-Einstein condensate is selected based on the most energetically stable stationary state. It is well known that for the homogeneous condensate linear and quadratic term plays an important role to lift the degeneracy among the stationary states, giving a rich phase diagram. In this article, we investigate the ground state in absence of linear and quadratic Zeeman terms under realistic trapping potential. The spin-dependent interaction strength plays a key role in favoring one of the stationary state to have the lowest energy and thus producing the ground state of the system. We notice that the Thomas-Fermi approximated results predict that for anti-ferromagnetic condensates the energy difference between the competing stationary states is really small, requiring further analysis considering the full profile of the condensate. Thus, for the purpose of further refining results, we introduce a variational method which provides the full number density profile of the condensate with very good accuracy even for small condensates in 3-dimensional isotropic harmonic confinement as well as in effective 1-dimensional harmonic trapping. Then we compare all the relevant physical parameters with those of Thomas-Fermi results.Comment: 17 pages, 13 figure

Unbounded Sharing of Nonlocality Using Projective Measurements

It is a common perception that a sharp projective measurement in one side of the Bell experiment destroys the entanglement of the shared state, thereby preventing the demonstration of sequential sharing of nonlocality. In contrast, we introduce a local randomness-assisted projective measurement protocol, enabling the sharing of nonlocality by an arbitrary number of sequential observers (Bobs) with a single spatially separated party Alice. Subsequently, a crucial feature of the interplay between the degrees of incompatibility of observables of both parties is revealed, enabling the unbounded sharing of nonlocality. Our findings, not only offer a new paradigm for understanding the fundamental nature of incompatibility in demonstrating quantum nonlocality but also pave a new path for various information processing tasks based on local randomness-assisted projective measurement

Au9+ swift heavy ion irradiation of Zn[CS(NH2)2]3SO4 crystal: Crystalline perfection and optical properties

The single crystal of tris(thiourea)zinc sulphate (Zn[CS(NH2)2]3SO4) was irradiated by 150 MeV Au9+ swift heavy ions and analyzed in comparison with pure crystal for crystalline perfection and optical properties. The Fourier transform infrared and x-ray powder diffraction inferred that swift ions lead the disordering and breaking of molecular bonds in lattice without formation of new structural phases. High resolution X-ray diffraction (HRXRD) revealed the abundance of point defects, and formation of mosaics and low angle grain boundaries in the irradiated region of crystal. The swift ion irradiation found to affect the lattice vibrational modes and functional groups significantly. The defects induced by heavy ions act as the color centers and resulted in enhance of photoluminescence emission intensity. The optical transparency and band gap found to be decreased.Comment: 7 page

Time allocation between paid and unpaid work among men and women: an empirical study of Indian villages

The paper examines the time allocation between paid work (wage earning or self-employed work generally termed as employment work) and unpaid (domestic chores/care work generally termed as non-employment work) along with wage rates, imputed earnings, and occupational structure among men and women and according to different social groups to establish the extent to which the rural labour market is discriminated by sex and social group. The major objective of the paper is to show the differential in wage income between men and women in farm and non-farm activities. The paper also shows the division of time between employment and non-employment activities by men and women. The paper uses high-frequency data and applies econometric techniques to know the factors behind time allocation among different activities across gender. The study finds that males spend more hours on employment work and work at a higher wage rate than females. As a result, a vast monetary income gap between men and women is observed, even though women worked more hours if employment and non-employment activities are jointly taken into consideration. Time spent on employment work and non-employment (mainly domestic chores) has been found to vary significantly due to social identity, household wealth, land, income, education, and skill. The segregation of labour market by sex was evident in this study, with men shifting to non-farm occupations with greater monetary returns and continued dependence on women’s farm activities. Enhancing the ownership of land and other assets, encouraging women’s participation particularly among minorities, and improving health are some of the policy recommendations directed from this study to enhance participation in employment work and shifting towards higher wage income employment.info:eu-repo/semantics/publishedVersio

A Hybrid model for the origin of photoluminescence from Ge nanocrystals in SiO2_2 matrix

In spite of several articles, the origin of visible luminescence from germanium nanocrystals in SiO$_2$ matrix is controversial even today. Some authors attribute the luminescence to quantum confinement of charge carriers in these nanocrystals. On the other hand, surface or defect states formed during the growth process, have also been proposed as the source of luminescence in this system. We have addressed this long standing query by simultaneous photoluminescence and Raman measurements on germanium nanocrystals embedded in SiO$_2$ matrix, grown by two different techniques: (i) low energy ion-implantation and (ii) atom beam sputtering. Along with our own experimental observations, we have summarized relevant information available in the literature and proposed a \emph{Hybrid Model} to explain the visible photoluminescence from nanocrystalline germanium in SiO$_2$ matrix.Comment: 23 pages, 8 figure