13,959 research outputs found
Topological Crystalline Bose Insulator in Two Dimensions via Entanglement Spectrum
Strongly correlated analogues of topological insulators have been explored in
systems with purely on-site symmetries, such as time-reversal or charge
conservation. Here, we use recently developed tensor network tools to study a
quantum state of interacting bosons which is featureless in the bulk, but
distinguished from an atomic insulator in that it exhibits entanglement which
is protected by its spatial symmetries. These properties are encoded in a model
many-body wavefunction that describes a fully symmetric insulator of bosons on
the honeycomb lattice at half filling per site. While the resulting integer
unit cell filling allows the state to bypass `no-go' theorems that trigger
fractionalization at fractional filling, it nevertheless has nontrivial
entanglement, protected by symmetry. We demonstrate this by computing the
boundary entanglement spectra, finding a gapless entanglement edge described by
a conformal field theory as well as degeneracies protected by the non-trivial
action of combined charge-conservation and spatial symmetries on the edge.
Here, the tight-binding representation of the space group symmetries plays a
particular role in allowing certain entanglement cuts that are not allowed on
other lattices of the same symmetry, suggesting that the lattice representation
can serve as an additional symmetry ingredient in protecting an interacting
topological phase. Our results extend to a related insulating state of
electrons, with short-ranged entanglement and no band insulator analogue.Comment: 18 pages, 13 figures Added additional reference
Single Photon Source with Individualized Single Photon Certifications
As currently implemented, single-photon sources cannot be made to produce
single photons with high probability, while simultaneously suppressing the
probability of yielding two or more photons. Because of this, single photon
sources cannot really produce single photons on demand. We describe a
multiplexed system that allows the probabilities of producing one and more
photons to be adjusted independently, enabling a much better approximation of a
source of single photons on demand. The scheme uses a heralded photon source
based on parametric downconversion, but by effectively breaking the trigger
detector area into multiple regions, we are able to extract more information
about a heralded photon than is possible with a conventional arrangement. This
scheme allows photons to be produced along with a quantitative
``certification'' that they are single photons. Some of the single-photon
certifications can be significantly better than what is possible with
conventional downconversion sources (using a unified trigger detector region),
as well as being better than faint laser sources. With such a source of more
tightly certified single photons, it should be possible to improve the maximum
secure bit rate possible over a quantum cryptographic link. We present an
analysis of the relative merits of this method over the conventional
arrangement.Comment: 11 pages, 5 figures, SPIE Free-Space Laser Communication and Laser
Imaging II. To appear in the proceeding of SPIE Free-Space Laser
Communication and Laser Imaging II, vol 482
CRIMES AND OFFENSES Bail Jumping: Redefine Offenses
The Act expands the crime of misdemeanor bail jumping to include defendants charged with or convicted any misdemeanor who fail to appear as directed. In addition, the Act creates the new offense of out-of-state bail jumping and provides notice procedures applicable to felony, misdemeanor, and out-of-state bail jumping
CRIMINAL PROCEDURE Death Penalty Cases: Provide for Review of Pretrial Proceedings
The Act provides for discretionary review by the Georgia Supreme Court of all pretrial proceedings in death penalty cases. In addition, the Act sets forth procedures to be followed in ordering and conducting such a review
CRIMINAL PROCEDURE Death Penalty Cases: Provide for Review of Pretrial Proceedings
The Act provides for discretionary review by the Georgia Supreme Court of all pretrial proceedings in death penalty cases. In addition, the Act sets forth procedures to be followed in ordering and conducting such a review
CRIMES AND OFFENSES State-Wide Probation Act: Revise Certain Provisions
The Act revises the State-Wide Probation Act by creating a maximum period for probation and suspended sentences, setting standards for the revocation of such sentences, and limiting the amount of time that can be revoked, depending on the offense that constitutes the violation
CRIMES AND OFFENSES State-Wide Probation Act: Revise Certain Provisions
The Act revises the State-Wide Probation Act by creating a maximum period for probation and suspended sentences, setting standards for the revocation of such sentences, and limiting the amount of time that can be revoked, depending on the offense that constitutes the violation
Literature Review on Modeling of Density Difference Pumping Strategy for Geothermal Applications
The utilization of geothermal ground heat sources has been demonstrated at both large and small scales across the world. However, methods of extraction of the hot working fluids are often a source of energy inefficiency and high capital expense. Current techniques to extract geothermal fluids rely on mechanically and electrically driven down-hole components that require maintenance on a regular basis. In providing a solution, one approach that reduces complexity, decreases maintenance, and allows access to fluids at greater depth is an airlift approach. The airlift approach relies on injection of gas at a depth within a geothermal well to lift the working fluid to the surface using a density difference pumping strategy.
This literature review focuses on existing methods and approaches to modeling the system throughout three scales: a microscale, intermediate scale, and macroscale. The microscale focuses on modeling considerations near the sparger head during bubble formation. The intermediate scale focuses on modeling techniques for characterizing bubble coalescing and gas hold-up. The macroscale focuses on modeling approaches over large length scales using a drift- flux model. Because of the varying phenomena experienced within the well, specifically complex bubble behavior and gas hold-up, it was a consensus amongst the literature to require a combination of in-depth experimental testing in combination with simulations to properly capture airlift flow rates.
This literature review provides a review of modeling approaches that could be used to design a geothermal airlift system. Overall, the airlift system has the potential future application for power generation, district heating, and residential heating/cooling in geographic regions previously not considered based on existing technologies. The computational tools are currently available but it will require in-depth study of geothermal fluids under two-phase flow regimes
Direct Determination of Thomson Coefficients in Single Crystal Zinc Rods
The Thomson coefficients for single crystal zinc as a function of the orientation of the principal crystal axis are being directly determined by Nettleton\u27s method. For a rod with an orientation angle of approximately 45° the coefficient shows a rise with increasing temperature over the range 50-250° C
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