243 research outputs found
Stop Running in LAPs: Evaluating the Lethality Assessment Program\u27s Effectiveness in Reducing Repeat Intimate Partner Violence
Repeat victimization is a phenomenon which is generally understood as the pattern and prevalence of victimization. This is an important factor for local authorities in their attempt to develop innovative policies and practices to facilitate predicting and preventing crimes. Thus, many police departments around the country, including the Las Vegas Metropolitan Police Department (LVMPD) have adopted the Lethality Assessment Program (LAP). This is a risk assessment tool used by responding officers on domestic violence calls that intends to prevent future risk of lethal violence to victims of domestic violence by assessing their risk of lethality and providing immediate referrals to social service providers. Furthermore, the overarching purpose of this research was to assess the nature and extent of repeat intimate partner violence in Las Vegas, Nevada, and to determine how LVMPD’s implementation of the LAP may impact repeat victimization. The sample consisted of 954 victims of intimate partner violence from January 2015. Results largely confirmed past research on repeat victimization: a small number of victims (9%) accounted for a large number of repeat victimizations (32%). Findings also indicated that when victims endured more than one previous intimate partner violence victimization, there was an increased risk of victimization for other crimes, as well as an increased risk to become a criminal offender. Additionally, findings revealed that past victims of intimate partner violence were less likely to receive a LAP Screen. However, when victims did receive a LAP Screen, the chances of enduring a future intimate partner violence victimization decreased. Implications and additional findings are discussed
Ultrafast polariton-phonon dynamics of strongly coupled quantum dot-nanocavity systems
We investigate the influence of exciton-phonon coupling on the dynamics of a
strongly coupled quantum dot-photonic crystal cavity system and explore the
effects of this interaction on different schemes for non-classical light
generation. By performing time-resolved measurements, we map out the
detuning-dependent polariton lifetime and extract the spectrum of the
polariton-to-phonon coupling with unprecedented precision. Photon-blockade
experiments for different pulse-length and detuning conditions (supported by
quantum optical simulations) reveal that achieving high-fidelity photon
blockade requires an intricate understanding of the phonons' influence on the
system dynamics. Finally, we achieve direct coherent control of the polariton
states of a strongly coupled system and demonstrate that their efficient
coupling to phonons can be exploited for novel concepts in high-fidelity single
photon generation
Complete Coherent Control of a Quantum Dot Strongly Coupled to a Nanocavity
Strongly coupled quantum dot-cavity systems provide a non-linear
configuration of hybridized light-matter states with promising quantum-optical
applications. Here, we investigate the coherent interaction between strong
laser pulses and quantum dot-cavity polaritons. Resonant excitation of
polaritonic states and their interaction with phonons allow us to observe
coherent Rabi oscillations and Ramsey fringes. Furthermore, we demonstrate
complete coherent control of a quantum dot-photonic crystal cavity based
quantum-bit. By controlling the excitation power and phase in a two-pulse
excitation scheme we achieve access to the full Bloch sphere. Quantum-optical
simulations are in good agreement with our experiments and provide insight into
the decoherence mechanisms
Restoring Lake Urmia: Moving beyond a Uniform Lake Level (2-page Summary)
More than 5 million people live near Lake Urmia in northwestern Iran, one of the world\u27s largest hypersaline lakes. Over the past two decades, the lake has lost 95% of its volume, lake level has dropped more than 7 m, and lake restoration has gained widespread interest. The government seeks a uniform ecological target lake level of 1274.1 m above sea level to lower salinity below 240 gL-1 and recover brine shrimp (Artemia spp.) and flamingos (Phoenicopterus roseus).
We have synthesized over 40 years of available data, defined 8 ecosystem services for human health, water quality, ecology, recreation, and economy (Box 1), and related each service to lake levels with uncertainties (Box 2)
On-chip architecture for self-homodyned nonclassical light
In the last decade, there has been remarkable progress on the practical integration of on-chip quantum photonic devices, yet quantum-state generators remain an outstanding challenge. Simultaneously, the quantum-dot photonic-crystal-resonator platform has demonstrated a versatility for creating nonclassical light with tunable quantum statistics thanks to a newly discovered self-homodyning interferometric effect that preferentially selects the quantum light over the classical light when using an optimally tuned Fano resonance. In this work, we propose a general structure for the cavity quantum electrodynamical generation of quantum states from a waveguide-integrated version of the quantum-dot photonic-crystal-resonator platform, which is specifically tailored for preferential quantum-state transmission. We support our results with rigorous finite-difference time-domain and quantum-optical simulations and show how our proposed device can serve as a robust generator of highly pure single- and even multiphoton states
Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers
We demonstrate a new approach for engineering group IV semiconductor-based
quantum photonic structures containing negatively charged silicon-vacancy
(SiV) color centers in diamond as quantum emitters. Hybrid SiC/diamond
structures are realized by combining the growth of nanoand micro-diamonds on
silicon carbide (3C or 4H polytype) substrates, with the subsequent use of
these diamond crystals as a hard mask for pattern transfer. SiV color
centers are incorporated in diamond during its synthesis from molecular diamond
seeds (diamondoids), with no need for ionimplantation or annealing. We show
that the same growth technique can be used to grow a diamond layer controllably
doped with SiV on top of a high purity bulk diamond, in which we
subsequently fabricate nanopillar arrays containing high quality SiV
centers. Scanning confocal photoluminescence measurements reveal optically
active SiV lines both at room temperature and low temperature (5 K) from
all fabricated structures, and, in particular, very narrow linewidths and small
inhomogeneous broadening of SiV lines from all-diamond nano-pillar arrays,
which is a critical requirement for quantum computation. At low temperatures (5
K) we observe in these structures the signature typical of SiV centers in
bulk diamond, consistent with a double lambda. These results indicate that high
quality color centers can be incorporated into nanophotonic structures
synthetically with properties equivalent to those in bulk diamond, thereby
opening opportunities for applications in classical and quantum information
processing
Self-homodyne-enabled generation of indistinguishable photons
The rapid generation of non-classical light serves as the foundation for exploring quantum optics and developing applications such as secure communications or the generation of NOON states. While strongly coupled quantum dot-photonic crystal resonator systems have great potential as non-classical light sources due to their promise of tailored output statistics, the generation of indistinguishable photons has been obscured due to the strongly dissipative nature of such systems. Here, we demonstrate that the recently discovered self-homodyne suppression technique can be used to overcome this limitation and tune the quantum statistics of transmitted light, achieving indistinguishable photon emission competitive with state-of-the-art metrics. Furthermore, our nanocavity-based platform directly lends itself to scalable on-chip architectures for quantum information
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