5,583 research outputs found
Emergent spacetimes from Hermitian and non-Hermitian quantum dynamics
We show that quantum dynamics of any systems with symmetry give
rise to emergent Anti-de Sitter spacetimes in 2+1 dimensions (AdS).
Using the continuous circuit depth, a quantum evolution is mapped to a
trajectory in AdS. Whereas the time measured in laboratories becomes
either the proper time or the proper distance, quench dynamics follow geodesics
of AdS. Such a geometric approach provides a unified interpretation of
a wide range of prototypical phenomena that appear disconnected. For instance,
the light cone of AdS underlies expansions of unitary fermions released
from harmonic traps, the onsite of parametric amplifications, and the
exceptional points that represent the 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 AdS.Comment: 6+3 pages, 3 figure
Analysis of Enterprise Behavior Game under the Condition of Carbon Taxes and New Energy Subsidies
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
Multipolar condensates and multipolar Josephson effects
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 -th order multipoles unavoidably creates a
condensate of the -th order multipoles, forming a hierarchy of
multipolar condensates that will offer physicists a whole new class of
macroscopic quantum phenomena
Synthetic tensor gauge fields
Synthetic gauge fields have provided physicists with a unique tool to explore
a wide range of fundamentally important phenomena in physics. However, only
synthetic vector gauge fields are currently available in experiments. The study
of tensor gauge fields, which play a vital role in fracton phase of matter,
remains purely theoretical. Here, we propose schemes to realize synthetic
tensor gauge fields using techniques readily available in laboratories. A
lattice tilted by a strong linear potential and a weak quadratic potential
naturally yields a rank-2 electric field for a lineon formed by a particle-hole
pair. Such a rank-2 electric field leads to a new type of Bloch oscillations,
where neither a single particle nor a single hole responds but a lineon
vibrates. A synthetic vector gauge field carrying a position-dependent phase
could also be implemented to produce the same synthetic tensor gauge field for
a lineon. In higher dimensions, the interplay between interactions and vector
gauge potentials imprints a phase to the ring-exchange interaction and thus
generates synthetic tensor gauge fields for planons. Such tensor gauge fields
make it possible to realize a dipolar Harper-Hofstadter model in laboratories.Comment: 6+3 pages, 4+3 figure
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