Frustration-driven QPT in the 1D extended anisotropic Heisenberg model

By using Density Matrix Renormalization Group (DMRG) technique we study the 1D extended anisotropic Heisenberg model. We find that starting from the ferromagnetic phase, the system undergoes two quantum phase transitions (QPTs) induced by frustration. By increasing the next-nearest-neighbor (NNN) interaction, the ground state of the system changes smoothly from a completely polarized state to a NNN correlated one. On the contrary, letting the in-plane interaction to be greater than the out-of-plane one, the ground state changes abruptly.Comment: 4 pages, 4 figures, to be presented at CSMAG-07 Kosice, Slovakia, July 200

Experimental evidence of strong phonon scattering in isotopical disordered systems: The case of LiH_xD_{1-x} crystals

The observation of the local - mode vibration, the two - mode behavior of the LO phonons at large isotope concentration, as well as large line broadening in LIH - D mixed crystals directly evidence strong additional phonon scattering due to the isotope - induced disorder.Comment: 9 pages, 4 figure

Does corruption matter for sources of foreign direct investment?

The paper provides a cross-country empirical analysis of the impact of corruption on foreign direct investment flows. The gravity model augmented with joint effects of corruption in the origin and destination countries determines differentiated patterns of investment flows between countries with various level of control of corruption. The estimates point towards greater investment flows between countries with good control of corruption. Moreover, if control of corruption in the destination country improves, investment flows from cleaner countries rise more than they do from countries with a higher incidence of corruption. The resulting changes in composition of investment volumes towards more investment from cleaner countries may further reinforce the strengthening of economic and political institutions that keep corruption in check

The discourse of the politics of memory in the Message of the President of Ukraine to the Verkhovna Rada in 1996 -2016 years.

This article describes how to use the theme of history in the President of Ukraine to the Verkhovna Rada. In this study, the method of content analysis which has shown what historical periods took place following links and what function they perform. Explains the historical trends over the past 20 years in the discourse of the presidents. Allocated individual characteristics of discursive practices of four presidents of Ukraine. Is paid attention to the connection of historical politics, ideology and discursive practices of political elites.Данная статья посвящена использованию тематики национального прошлого в посланиях Президентов Украины к Верховной Раде. При помощи контент анализа показано, к каким историческим периодам происходят отсылки и исполняемые ими функции. Продемонстрированы общие тенденции изменения обращения к историческим темам в посланиях президентов за последние 20 лет. Рассматриваются индивидуальные особенности дискурсивных практик четырёх президентов Украины. Обращается внимание на связь исторической политики, идеологии и дискурсивных практик политических элит.Исследование выполнено при поддержке Российского научного фонда, грант № 15-18-00099

Efficiency of photodesorption of Rb atoms collected on polymer organic film in vapor-cell

The efficiency of photodesorption of Rb atoms previously collected on polymer organic film has been studied in detail. This study was carried out in a Pyrex glass cell of which the inner surface was covered with (poly)dimethylsiloxane (PDMS) film and illuminated by a powerful flash lamp. The desorption dynamic of the Rb atoms density in the cell caused by the illumination and percentage of desorbed atoms was studied by using of Rb resonance lamp and free running diode laser as sources of probing light. It was determined that 85 percent collected chemical active Rb atoms and stored during 16 seconds in the closed cell, 75 percent in the pumped cell can be desorbed by single flash of the lamp. The number of stored atoms decays with a characteristic time of 60 min in isolated cell and with a time 12.4 minutes in a pumped cell. We believe that this efficient method of collection and fast realization of atoms or molecules could be used for enhancement of sensitivity of existed sensors for the trace detection of various elements (including toxic or radioactive ones) which is important to environmental applications, medicine or in geology. The effect might help to construct an efficient light-driven atomic source for a magneto-optical trap in a case of extremely low vapor density or very weak flux of atoms, such as artificial radioactive alkali atoms.Comment: 9 pages, 9 figures; accepted for publication in EPJ