5,221 research outputs found

    Emergent spacetimes from Hermitian and non-Hermitian quantum dynamics

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    We show that quantum dynamics of any systems with SU(1,1)SU(1,1) symmetry give rise to emergent Anti-de Sitter spacetimes in 2+1 dimensions (AdS2+1_{2+1}). Using the continuous circuit depth, a quantum evolution is mapped to a trajectory in AdS2+1_{2+1}. Whereas the time measured in laboratories becomes either the proper time or the proper distance, quench dynamics follow geodesics of AdS2+1_{2+1}. Such a geometric approach provides a unified interpretation of a wide range of prototypical phenomena that appear disconnected. For instance, the light cone of AdS2+1_{2+1} underlies expansions of unitary fermions released from harmonic traps, the onsite of parametric amplifications, and the exceptional points that represent the PTPT symmetry breaking in non-Hermitian systems. Our work provides a transparent means to optimize quantum controls by exploiting shortest paths in the emergent spacetimes. It also allows experimentalists to engineer emergent spacetimes and induce tunnelings between different AdS2+1_{2+1}.Comment: 6+3 pages, 3 figure

    Analysis of Enterprise Behavior Game under the Condition of Carbon Taxes and New Energy Subsidies

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    In this paper, a dynamic game model of duopoly firms between the traditional electric power enterprises and new energy enterprises was established for analyzing the behaviors of electric power enterprises under different government carbon taxes policies and the corresponding Nash equilibrium. This goal of the model was set to maximize the total social welfare while considering the economic, social and environmental benefit. This model was further used to calculate the optimal carbon tax rate and optimal government subsidy level for both traditional electric power enterprises and new energy enterprises. The results showed that a reasonable carbon tax rate and return mode can optimize the structure of Chinese power industry, encouraging the high-carbon enterprises to reduce emission, promote the development of low carbon enterprises, and reduce the overall carbon dioxide emission from the power industry

    Utility of Landsat Image in the Study of Land Cover and Land Surface Temperature Change

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    AbstractScientists have aimed at exploring land use and land cover (LULC) and their environmental influence in order to improve our understanding of the causes and consequences of these phenomena. This study addresses and use and land cover change (LUCC) in the upper reaches of Pearl River Delta, China, from 1990 to 2008. Based on remotely sensed images of Landsat, LUCC and land surface temperature were assessed. Results showed that land surface temperature was highly influenced by the LUCC from 1990 to 2008. An examination of the relationship between the LULC and LST maps was finally conducted to comprehension their interactions. Results indicated that Landsat image was effective for quantifying the heat environment and providing reliable measurements of land use change. LST was found to be positively correlated with impervious surface but negatively correlated with vegetated land. Each temperature zone was associated with a dominant LULC category

    Multipolar condensates and multipolar Josephson effects

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    When single-particle dynamics are suppressed in certain strongly correlated systems, dipoles arise as elementary carriers of quantum kinetics. These dipoles can further condense, providing physicists with a rich realm to study fracton phases of matter. Whereas recent theoretical discoveries have shown that an unconventional lattice model may host a dipole condensate as the ground state, fundamental questions arise as to whether dipole condensation is a generic phenomenon rather than a specific one unique to a particular model and what new quantum macroscopic phenomena a dipole condensate may bring us with. Here, we show that dipole condensates prevail in bosonic systems. Because of a self-proximity effect, where single-particle kinetics inevitably induces a finite order parameter of dipoles, dipole condensation readily occurs in conventional normal phases of bosons. Our findings allow experimentalists to manipulate the phase of a dipole condensate and deliver dipolar Josephson effects, where supercurrents of dipoles arise in the absence of particle flows. The self-proximity effects can also be utilized to produce a generic multipolar condensate. The kinetics of the nn-th order multipoles unavoidably creates a condensate of the (n+1)(n+1)-th order multipoles, forming a hierarchy of multipolar condensates that will offer physicists a whole new class of macroscopic quantum phenomena
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