7,212 research outputs found
Universal quantum gates between nitrogen-vacancy centers in a levitated nanodiamond
We propose a scheme to realize universal quantum gates between
nitrogen-vacancy (NV) centers in an optically trapped nanodiamond, through
uniform magnetic field induced coupling between the NV centers and the
torsional mode of the levitated nanodiamond. The gates are tolerant to the
thermal noise of the torsional mode. By combining the scheme with dynamical
decoupling technology, it is found that the high fidelity quantum gates are
possible for the present experimental conditions. The proposed scheme is useful
for NV-center-based quantum network and distributed quantum computationComment: 7 pages, 6 figure
Leveraging Interactions for Stationary and Dynamic Financial Distress Prediction: A Spatio-Temporal Financial Graph Attention Network
Financial distress prediction is a prominent research topic in information systems, with two primary modelling categories: stationary and dynamic modelling. Recent stationary modelling works have leveraged company interactions to improve prediction performance, considering the heterogeneity of interactions while ignoring the dynamicity. However, few dynamic modelling works utilized interactions. To address the inconsistency and limitation of stationary and dynamic modelling works in leveraging interactions, we propose the Spatio-Temporal Financial Graph Attention Network with Meta-learning (STFGAN-Meta). STFGAN-Meta leverages interactions\u27 spatial heterogeneity via the Spatial Aggregation module and temporal dynamicity via the Temporal Aggregation module. STFGAN-Meta introduces the Meta-learning Optimization module to unify stationary and dynamic modelling. Our experimental evaluation demonstrates that leveraging dynamicity and heterogeneity of interactions outperforms leveraging dynamicity or heterogeneity alone. Meta-learning succeeds in providing a generalized approach between stationary and dynamic modelling. STFGAN-Meta can be a promising risk assessment and decision-making tool in the financial industry
Properties of the scalar mesons , and
In the three-state mixing framework, considering the possible glueball
components of and , we investigate the hadronic decays of
, and into two pseudoscalar mesons. The
quarkonia-glueball content of the three states is determined from the fit to
the new data presented by the WA102 Collaboration. We find that these data are
insensitive to the possible glueball components of and .
Furthermore, we discuss some properties of the mass matrix describing the
mixing of the isoscalar scalar mesons.Comment: Latex 14 pages including 1 eps figur
Building a Data Infrastructure to Study Local Availability in Childcare for Children of Immigrant and U.S.-Born Parents: A Conditional Logit Model Analysis
In the United States, children of immigrants are more likely to start school at an academic disadvantage when compared to their peers with U.S.-born parents (Crosnoe, 2007; Han, 2008; Magnuson, Lahaie, & Waldfogel, 2006). It is possible that the disadvantage may be at least in part explained by differences in access to and use of high-quality childcare opportunities prior to the Kindergarten year. Indeed, while research has pointed to the benefits associated with high-quality early childhood education and public investments in expanding preschool enrollment, the children of immigrants continue to enroll in center-based care at lower rates compared to the children of U.S.-born parents (Brandon, 2004; Kahn & Greenberg, 2010; Karoly & Gonzalez, 2011; Takanishi, 2004). This study seeks to understand whether and how the supply of childcare services available in a neighborhood and other contextual factors contribute to differences in early education experiences by parental immigration status. Building a first of its kind dataset, I combined data from the Early Childhood Longitudinal Study, the Common Core of Data, the Early Childhood Learning and Knowledge Center Head Start Data Project, the Homeland Infrastructure Foundation-Level Data, and the U.S. Census Bureau to examine whether and how childcare supply affects childcare use between immigrant and U.S.-born parents. Using a conditional logit model, I find that the supply of childcare centers, Head Start, and state pre-K programs differs between children of immigrant and U.S.-born parents, and the supply of childcare centers, in particular, had differential effects on center enrollment by parental immigration status. Having at least one immigrant parent negatively impacted the odds of center participation, and, even having more access to childcare centers could not offset its negative effect. Implications of these findings and recommendations to improve the overall data quality are discussed.Doctor of Philosoph
Nonadiabatic dynamics and geometric phase of an ultrafast rotating electron spin
The spin in a rotating frame has attracted a lot of attentions recently, as
it deeply relates to both fundamental physics such as pseudo-magnetic field and
geometric phase, and applications such as gyroscopic sensors. However, previous
studies only focused on adiabatic limit, where the rotating frequency is much
smaller than the spin frequency. Here we propose to use a levitated
nano-diamond with a built-in nitrogen-vacancy (NV) center to study the dynamics
and the geometric phase of a rotating electron spin without adiabatic
approximation. We find that the transition between the spin levels appears when
the rotating frequency is comparable to the spin frequency at zero magnetic
field. Then we use Floquet theory to numerically solve the spin energy
spectrum, study the spin dynamics and calculate the geometric phase under a
finite magnetic field, where the rotating frequency to fulfill the resonant
transition condition could be greatly reduced.Comment: 6+2 pages, 3+1 figure
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