Heating up quadruply quantized vortices: Splitting patterns and dynamical transitions

Using holographic duality, we investigate the impact of finite temperature on the instability and splitting patterns of quadruply quantized vortices, providing the first-ever analysis in this context. Through linear stability analysis, we reveal the occurrence of two consecutive dynamical transitions. At a specific low temperature, the dominant unstable mode transitions from the $2$-fold rotational symmetry mode to the $3$-fold one, followed by a transition from the $3$-fold one to the $4$-fold one at a higher temperature. As the temperature is increased, we also observe the $5$ and $6$-fold rotational symmetry unstable modes get excited successively. Employing the full non-linear numerical simulations, we further demonstrate that these two novel dynamical transitions, along with the temperature-induced instabilities for the $5$ and $6$-fold rotational symmetry modes, can be identified by examining the resulting distinct splitting patterns, which offers a promising route for the experimental verification in the cold atom gases.Comment: 10 pages,8 figures, version to appear in Physical Review Letter

Barriers of effective health insurance coverage for rural-to-urban migrant workers in China: a systematic review and policy gap analysis.

BACKGROUND: More than 90% of the Chinese population was covered by its three basic social health insurances. However, the Chinese rural-to-urban migrant workers (RUMWs), accounting for about one-fifth of China's total population, seem to be put on a disadvantaged position under the current health insurance schemes. The purpose of this study is to identify the current barriers and to provide policy suggestions to the ineffective health insurance coverage of RUMWs in China. METHODS: A systematic review guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The searched databases included PubMed, Embase, Medline, Web of Science, PsycINFO, Maternity and Infant Care Database MIDIRS, the Cochrane Library, WHO Library Database (WHOLIS), WHO Global Health Library, World Bank eLibrary, OpenGrey, CNKI, and Wanfang. In total, 70 articles were reviewed. RESULTS: (1) Chinese RUMWs have high work mobility and low job stability; (2) Barriers faced by RUMWs in obtaining effective health insurance coverage are primarily due to the reluctance of employers to provide insurance for all employees and the disadvantaged position held by RUMWs when negotiating with their employers; (3) Fissures among existing health insurance schemes leaves no room for RUMWs to meet their primary needs; and (4) Recent efforts in improving the portability and transferability of insurance across borders and schemes are not enough to solve the barriers. CONCLUSION: It is argued that the Chinese central government must deal with the fragmentation of healthcare system in China and promote effective coverage by: (1) playing a more active role in coordinating different healthcare and social welfare schemes across the country, (2) increasing the health insurance portability, (3) making the healthcare policies more compatible with RUMW's characteristics to meet their primary health needs, (4) strengthening supervision of employers, and (5) providing more vocational training and other support to increase RUMW's job stability

Barriers of effective health insurance coverage for rural-to-urban migrant workers in China: a systematic review and policy gap analysis.

BACKGROUND: More than 90% of the Chinese population was covered by its three basic social health insurances. However, the Chinese rural-to-urban migrant workers (RUMWs), accounting for about one-fifth of China's total population, seem to be put on a disadvantaged position under the current health insurance schemes. The purpose of this study is to identify the current barriers and to provide policy suggestions to the ineffective health insurance coverage of RUMWs in China. METHODS: A systematic review guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The searched databases included PubMed, Embase, Medline, Web of Science, PsycINFO, Maternity and Infant Care Database MIDIRS, the Cochrane Library, WHO Library Database (WHOLIS), WHO Global Health Library, World Bank eLibrary, OpenGrey, CNKI, and Wanfang. In total, 70 articles were reviewed. RESULTS: (1) Chinese RUMWs have high work mobility and low job stability; (2) Barriers faced by RUMWs in obtaining effective health insurance coverage are primarily due to the reluctance of employers to provide insurance for all employees and the disadvantaged position held by RUMWs when negotiating with their employers; (3) Fissures among existing health insurance schemes leaves no room for RUMWs to meet their primary needs; and (4) Recent efforts in improving the portability and transferability of insurance across borders and schemes are not enough to solve the barriers. CONCLUSION: It is argued that the Chinese central government must deal with the fragmentation of healthcare system in China and promote effective coverage by: (1) playing a more active role in coordinating different healthcare and social welfare schemes across the country, (2) increasing the health insurance portability, (3) making the healthcare policies more compatible with RUMW's characteristics to meet their primary health needs, (4) strengthening supervision of employers, and (5) providing more vocational training and other support to increase RUMW's job stability

Towards an effective description of holographic vortex dynamics

Although holographic duality has been regarded as a complementary tool in helping understand the non-equilibrium dynamics of strongly coupled many-body systems, it still remains an open question how to confront its predictions quantitatively with the real experimental scenarios. By taking a right evolution scheme for the holographic superfluid model and matching the holographic data with the phenomenological dissipative Gross-Pitaeviskii models, we find that the holographic dissipation mechanism can be well captured by the Landau form, which is expected to greatly facilitate the quantitative test of the holographic predictions against the upcoming experimental data. Our result also provides a prime example how holographic duality can help select proper phenomenological models by invalidating the claim made in the previous literature that the Keldysh self energy can serve as an effective description of the holographic dissipation in superfluids.Comment: 7 pages, 10 figures, 1 table; minor improvements with typos correcte

Splitting of doubly quantized vortices in holographic superfluid of finite temperature

The temperature effect on the linear instability and the splitting process of a doubly quantized vortex is studied. Using the linear perturbation theory to calculate out the quasi-normal modes of the doubly quantized vortex, we find that the imaginary part of the unstable mode increases with the temperature till some turning temperature, after which the imaginary part of the unstable mode decreases with the temperature. On the other hand, by the fully non-linear numerical simulations, we also examine the real time splitting process of the doubly quantized vortex, where not only do the split singly quantized vortex pair depart from each other, but also revolve around each other. In particular, the characteristic time scale for the splitting process is identified and its temperature dependence is found to be in good agreement with the linear instability analysis in the sense that the larger the imaginary part of the unstable mode is, the longer the splitting time is. Such a temperature effect is expected to be verified in the cold atom experiments in the near future.Peer reviewe