78 research outputs found

    Motional NN-phonon Bundle States of A Trapped Atom with Clock Transitions

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    Quantum manipulation of individual phonons could offer new resources for studying fundamental physics and creating an innovative platform in quantum information science. Here, we propose to generate quantum states of strongly correlated phonon bundles associated with the motion of a trapped atom. Our scheme operates in the atom-phonon resonance regime where the energy spectrum exhibits strong anharmonicity such that energy eigenstates with different phonon numbers can be well-resolved in the parameter space. Compared to earlier schemes operating in the far dispersive regime, the bundle states generated here contain a large steady-state phonon number. Therefore, the proposed system can be used as a high quality multiphonon source. Our results open up the possibility of using long-lived motional phonons as quantum resources, which could provide a broad physics community for applications in quantum metrology

    Unidirectionally Structured Magnetic Phase-Change Composite Based on Carbonized Polyimide/Kevlar Nanofiber Complex Aerogel for Boosting Solar-Thermo-Electric Energy Conversion

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    To realize highly efficient solar-thermo-electric energy conversion for clean electricity power generation, we have developed a new type of unidirectionally structured magnetic phase-change composite comprising a carbonized polyimide (C–PI)/Kevlar nanofiber (KNF) complex aerogel as a 3D carbon skeleton porous supporting material, CoFe2O4 nanoparticles as a magnetic additive, polyethylene glycol (PEG) as a phase-change material, and polypyrrole as a photothermal absorption coating layer. The as-fabricated C–PI/KNF complex aerogel exhibits a unidirectional microstructure, high porosity, robust skeleton frame, ultralight weight, and high thermal conductance. Featured with such unique structure and characteristics, the complex aerogel can offer an effective heat and electron transfer method to ensure highly efficient solar-thermal conversion and photothermal energy storage of the developed composite. The developed composite exhibits a high latent heat capacity of over 150 J g–1, outstanding shape stability along with a low leakage of 0.2 wt %, good thermal cycling stability, and high photothermal conversion efficiency of 84.8%. Based on the Seebeck effect, a solar thermoelectric generation system (STEGS) was constructed with the hot side coupled with the developed composite and the cold side immersed in air and ice water. Under 2.0 kW m–2 solar irradiation, the developed STEGS in ice water obtained maximum output voltage and current of 259.7 mV and 27.1 mA, respectively, which are significantly higher than those in air. The output power of the developed STEGS in an ice water environment is 50.6% higher than that in air under 4.0 kW m–2 solar irradiation. More importantly, the developed STEGS in ice water continuously generated output voltage and current for about 810 s without solar irradiation thanks to the latent heat release by the PEG component within the developed composite. In addition, the introduction of magnetic CoFe2O4 can accelerate solar-thermal conversion through periodic electron motion by the Néel relaxation or Brownian relaxation. This resulted in an increase in the maximum output voltage and current by 13.7 and 11.5%, respectively, under an alternating magnetic field as a result of the magnetism-accelerated solar-thermo-electric conversion. This study offers an innovative approach for developing PCM-based advanced functional materials for solar energy utilization in clean and sustainable electricity generation

    Topology-Enhanced Nonreciprocal Scattering and Photon Absorption in a Waveguide

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    Topological matter and topological optics have been studied in many systems, with promising applications in materials science and photonics technology. These advances motivate the study of the interaction between topological matter and light, as well as topological protection in light-matter interactions. In this work, we study a waveguide-interfaced topological atom array. The light-matter interaction is nontrivially modified by topology, yielding novel optical phenomena. We find topology-enhanced photon absorption from the waveguide for large Purcell factor, i.e., Γ/Γ01\Gamma/\Gamma_0\gg 1, where Γ\Gamma and Γ0\Gamma_0 are the atomic decays to waveguide and environment, respectively. To understand this unconventional photon absorption, we propose a multi-channel scattering approach and study the interaction spectra for edge- and bulk-state channels. We find that, by breaking inversion and time-reversal symmetries, optical anisotropy is enabled for reflection process, but the transmission is isotropic. Through a perturbation analysis of the edge-state channel, we show that the anisotropy in the reflection process originates from the waveguide-mediated non-Hermitian interaction. However, the inversion symmetry in the non-Hermitian interaction makes the transmission isotropic. At a topology-protected atomic spacing, the subradiant edge state exhibits huge anisotropy. Due to the interplay between edge- and bulk-state channels, a large topological bandgap enhances nonreciprocal reflection of photons in the waveguide for weakly broken time-reversal symmetry, i.e., Γ0/Γ1\Gamma_0/\Gamma\ll 1, producing complete photon absorption. We show that our proposal can be implemented in superconducting quantum circuits. The topology-enhanced photon absorption is useful for quantum detection. This work shows the potential to manipulate light with topological quantum matter

    Mn<sup>II</sup> Complexes with a Novel Triacid as Ligand: Synthesis and Characterization

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    <div><p>A novel aromatic tricarboxylic acid of 4,4′-(2-carboxypropane-1,3-diyl)dibenzoic acid (H<sub>3</sub>L) was used to prepare two Mn<sup>II</sup> complexes of [Mn<sub>3</sub>(L)<sub>2</sub>(bpy)<sub>2</sub>]<sub>n</sub> (<b>1</b>) and [Mn<sub>3</sub>(L)<sub>2</sub>(phen)<sub>2</sub>]<sub>n</sub> (<b>2</b>), where bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline. The single crystal structures, thermal stability, and the magnetism of <b>1</b> and <b>2</b> were measured and discussed in this article. According to the magnetism measurements, the Curie constants and the Weiss constants should be 12.29 K·cm<sup>3</sup>·mol<sup>−1</sup> (g = 1.94, S = 5/2) and −9.80 K for <b>1</b> and 11.11 K·cm<sup>3</sup>·mol<sup>−1</sup> (g = 1.83, S = 5/2) and −9.26 K for <b>2</b>, respectively.</p></div

    Legislative Documents

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    Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents

    Highly Stable Polyaniline-Based Cathode Material Enabled by Phosphorene for Zinc-Ion Batteries with Superior Specific Capacity and Cycle Life

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    Aqueous zinc-ion batteries (ZIBs) are regarded as a type of promising energy-storage device because of their high safety and low cost, and polyaniline (PANI) is normally employed as a cathode material for ZIBs owing to its unique electrochemical properties and high environmental stability. However, a low specific capacity and a short cycle life limit the development and applications of PANI-based electrodes. Herein, we have developed a novel type of highly stable PANI-based cathode material enabled by phosphene (PR) for aqueous Zn-PANI batteries through in situ chemical oxidative polymerization. The introduction of PR nanoflakes not only inhibits the degradation of PANI and generates more active sites for Zn2+ storage but also enables a synergistic effect of the Zn2+ insertion/extraction and P–Zn alloying reaction. This promotes a high reversible specific capacity of 240.2 mAh g–1 at 0.2 A g–1 and excellent rate performance for the PR/PANI nanocomposite cathode material. Compared to the pristine PANI cathode material, the PR/PANI nanocomposite cathode material is more suitable for the Zn-PANI battery, thanks to its higher specific capacity and better cycle stability. This study provides an innovative approach for developing the next generation of reliable PR-based electrode materials for aqueous energy-storage devices

    Data_Sheet_1_Genome-wide association study of traits in sacred lotus uncovers MITE-associated variants underlying stamen petaloid and petal number variations.PDF

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    Understanding the genetic variants responsible for floral trait diversity is important for the molecular breeding of ornamental flowers. Widely used in water gardening for thousands of years, the sacred lotus exhibits a wide range of diversity in floral organs. Nevertheless, the genetic variations underlying various morphological characteristics in lotus remain largely unclear. Here, we performed a genome-wide association study of sacred lotus for 12 well-recorded ornamental traits. Given a moderate linkage disequilibrium level of 32.9 kb, we successfully identified 149 candidate genes responsible for seven flower traits and plant size variations, including many pleiotropic genes affecting multiple floral-organ-related traits, such as NnKUP2. Notably, we found a 2.75-kb presence-and-absence genomic fragment significantly associated with stamen petaloid and petal number variations, which was further confirmed by re-examining another independent population dataset with petal number records. Intriguingly, this fragment carries MITE transposons bound by siRNAs and is related to the expression differentiation of a nearby candidate gene between few-petalled and double-petalled lotuses. Overall, these genetic variations and candidate genes responsible for diverse lotus traits revealed by our GWAS highlight the role of transposon variations, particularly MITEs, in shaping floral trait diversity.</p
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