1,077 research outputs found
Detailed simulations of lighting conditions in office rooms lit by daylight and artificial light
Tower of quantum scars in a partially many-body localized system
Isolated quantum many-body systems are often well-described by the eigenstate
thermalization hypothesis. There are, however, mechanisms that cause different
behavior: many-body localization and quantum many-body scars. Here, we show how
one can find disordered Hamiltonians hosting a tower of scars by adapting a
known method for finding parent Hamiltonians. Using this method, we construct a
spin-1/2 model which is both partially localized and contains scars. We
demonstrate that the model is partially localized by studying numerically the
level spacing statistics and bipartite entanglement entropy. As disorder is
introduced, the adjacent gap ratio transitions from the Gaussian orthogonal
ensemble to the Poisson distribution and the entropy shifts from volume-law to
area-law scaling. We investigate the properties of scars in a partially
localized background and compare with a thermal background. At strong disorder,
states initialized inside or outside the scar subspace display different
dynamical behavior but have similar entanglement entropy and Schmidt gap. We
demonstrate that localization stabilizes scar revivals of initial states with
support both inside and outside the scar subspace. Finally, we show how strong
disorder introduces additional approximate towers of eigenstates.Comment: 18 pages, 12 figures, v2: accepted versio
Occupants’ satisfaction with the visual environment in a single office with individual lighting and solar shading control
The effect of different weather data sets and their resolution in climate-based daylight modeling for the location of Copenhagen
Role of p38 mitogen-activated protein kinase isoforms in murine skin inflammation induced by 12-O-tetradecanoylphorbol 13-acetate
Approximate Hofstadter- and Kapit-Mueller-like parent Hamiltonians for Laughlin states on fractals
Recently, it was shown that fractional quantum Hall states can be defined on
fractal lattices. Proposed exact parent Hamiltonians for these states are
nonlocal and contain three-site terms. In this work, we look for simpler,
approximate parent Hamiltonians for bosonic Laughlin states at half filling,
which contain only onsite potentials and two-site hopping with the interaction
generated implicitly by hardcore constraints (as in the Hofstadter and
Kapit-Mueller models on periodic lattices). We use an ``inverse method'' to
determine such Hamiltonians on finite-generation Sierpi\'{n}ski carpet and
triangle lattices. The ground states of some of the resulting models display
relatively high overlap with the model states if up to third neighbor hopping
terms are considered, and by increasing the maximum hopping distance one can
achieve nearly perfect overlaps. When the number of particles is reduced and
additional potentials are introduced to trap quasiholes, the overlap with a
model quasihole wavefunction is also high in some cases, especially for the
nonlocal Hamiltonians. We also study how the small system size affects the
braiding properties for the model quasihole wavefunctions and perform analogous
computations for Hamiltonian models.Comment: Version accepted in Phys. Rev. A. See the Ancillary Files for the
Supplementary Materia
A Visit to the ' New Utopia':Revitalizing Democracy, Emancipaction, and Quality in Co-operative Design
Erindringens kontemporaneitet
En arkiv- og medieteoretisk analyse af kunstneriske forhandlinger af individuationens vilkår mellem dokumentalitet og medieøkologi
Escaping many-body localization in an exact eigenstate
Isolated quantum systems typically follow the eigenstate thermalization
hypothesis, but there are exceptions, such as many-body localized (MBL) systems
and quantum many-body scars. Here, we present the study of a weak violation of
MBL due to a special state embedded in a spectrum of MBL states. The special
state is not MBL since it displays logarithmic scaling of the entanglement
entropy and of the bipartite fluctuations of particle number with subsystem
size. In contrast, the bulk of the spectrum becomes MBL as disorder is
introduced. We establish this by studying the entropy as a function of disorder
strength and by observing that the level spacing statistics undergoes a
transition from Wigner-Dyson to Poisson statistics as the disorder strength is
increased.Comment: 8 pages, 7 figure
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