We generalize 1+1-dimensional formalism derived by Ahmadi et al. Phys. Rev. D 93, 124031 (2016) to investigate an effect of relativistic acceleration on localized two-mode Gaussian quantum states in ...3+1-dimensional spacetime. The following framework is then used to analyze entanglement of the Minkowski vacuum as witnessed by two accelerating observers that move either collinearly or noncollinearly.
We study a binary spin mixture of a zero-temperature repulsively interacting ^{6}Li atoms using both the atomic-orbital and density-functional approaches. The gas is initially prepared in a ...configuration of two magnetic domains and we determine the frequency of the spin-dipole oscillations which are emerging after the repulsive barrier, initially separating the domains, is removed. We find, in agreement with recent experiment G. Valtolina et al., Nat. Phys. 13, 704 (2017)NPAHAX1745-247310.1038/nphys4108, the occurrence of a ferromagnetic instability in an atomic gas while the interaction strength between different spin states is increased, after which the system becomes ferromagnetic. The ferromagnetic instability is preceded by the softening of the spin-dipole mode.
We report on the nonlinear optical signatures of quantum phase transitions in the high-temperature superconductor YBCO, observed through high harmonic generation. While the linear optical response of ...the material is largely unchanged when cooling across the phase transitions, the nonlinear optical response sensitively imprints two critical points, one at the critical temperature of the cuprate with the exponential growth of the surface harmonic yield in the superconducting phase and another critical point, which marks the transition from strange metal to pseudogap phase. To reveal the underlying microscopic quantum dynamics, a strong-field quasi-Hubbard model was developed, which describes the measured optical response dependent on the formation of Cooper pairs. Further, the theory provides insight into the carrier scattering dynamics and allows us to differentiate between the superconducting, pseudogap, and strange metal phases. The direct connection between nonlinear optical response and microscopic dynamics provides a powerful methodology to study quantum phase transitions in correlated materials. Further implications are light wave control over intricate quantum phases, light–matter hybrids, and application for optical quantum computing.
We investigate how relativistic acceleration of the observers can affect the performance of the quantum teleportation and dense coding for continuous variable states of localized wave packets. Such ...protocols are typically optimized for symmetric resources prepared in an inertial frame of reference. A mismatch of the sender’s and the receiver’s accelerations can introduce asymmetry to the shared entanglement, which has an effect on the efficiency of the protocol that goes beyond entanglement degradation due to acceleration. We show how these asymmetry losses can be reduced by an extra local operations and classical communication (LOCC) step in the protocols.
We predict the phase separations of two-dimensional Fermi gases with repulsive contact-type interactions between two spin components. Using density-potential functional theory with systematic ...semiclassical approximations, we address the long-standing problem of itinerant ferromagnetism in realistic settings. We reveal a universal transition from the paramagnetic state at small repulsive interactions toward ferromagnetic density profiles at large interaction strengths, with intricate particle-number dependent phases in between. Building on quantum Monte Carlo results for uniform systems, we benchmark our simulations against Hartree–Fock calculations for a small number of trapped fermions. We thereby demonstrate that our employed corrections to the bare contact interaction energy and especially to the Thomas–Fermi kinetic energy functional are necessary for reliably predicting properties of trapped mesoscopic Fermi gases. The density patterns of the ground state survive at low finite temperatures and confirm the Stoner-type polarization behavior across a universal interaction parameter, albeit with substantial quantitative differences that originate in the trapping potential and the quantum-corrected kinetic energy. We also uncover a plethora of metastable configurations that are energetically comparable to the ground-state density profiles and are thus likely to be observed in experiments. We argue that our density-functional approach can be easily applied to interacting multi-component Fermi gases in general.
MARIA BALISZEWSKA etnomuzykolożka i dziennikarka. Od roku 1973 roku pracuje w Polskim Radiu. Autorka wielu audycji o tematyce ludowej i nagrań polskiego folkloru muzycznego oraz nagrań studyjnych i ...festiwalowych. Założycielka i kierowniczka Radiowego Centrum Kultury Ludowej (1994-2007), koordynatorka Europejskiej Unii Radiowej ds. muzyki tradycyjnej i folkowej (1998-2009), jurorka festiwali i przeglądów muzyki tradycyjnej (m.in. Ogólnopolskiego Festiwalu Kapel i Śpiewaków Ludowych w Kazimierzu oraz Międzynarodowego Konkursu Kapel, Instrumentalistów i Śpiewaków Ludowych w Zakopanem). W 1998 roku z jej inicjatywy powstał Folkowy Festiwal Polskiego Radia „Nowa Tradycja”. Autorka wielu płyt z serii Muzyka Źródeł wydawanej przez Polskie Radio, a także innych albumów, m.in. Pod Tatrami, Polskie instrumenty ludowe, Welcome Europe. Członkini Związku Kompozytorów Polskich oraz Rady Naukowej Stowarzyszenia Twórców Ludowych. Uhonorowana m.in. Złotym Mikrofonem (1993), medalem Zygmunta Glogera (2003) ), nagrodą Ministra Kultury i Dziedzictwa Narodowego (2007) oraz nagrodą im. Oskara Kolberga (2014).
Jacek Jackowski is a musician and ethnomusicologist, and the head of the Phonographic Collection at the Institute of Art of the Polish Academy of Sciences. He specializes in the conservation, ...digitization and archiving of old sound recordings. He is a field researcher and author of many academic articles on traditional, Catholic and folk religious culture associated with musical behaviours. He also published numerous articles and books on early folk music recordings and their digitization (Zachować dawne nagrania, Warszawa 2014; Polska muzyka tradycyjna – dziedzictwo fonograficzne, t. 1, Warszawa 2017; t. 2, Warszawa 2019), as well as 17 CD albums of folk songs and music from Kashubia, Kurpie, Podhale, Łowicz, Orava, South Wielkopolska and many other regions of Poland. Since 2014 he has been managing the Etnofon project, the goal of which is to create, develop and maintain a central digital repository of documentary phonographic and film recordings capturing Polish traditional songs and music as well as folk dance.
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