Exact Hole-induced Resonating-Valence-Bond Ground State in Certain U=∞U=\infty Hubbard Models

We prove that the motion of a single hole induces the nearest-neighbor resonating-valence-bond ground state in the $U=\infty$ Hubbard model on a triangular cactus - a tree-like variant of a kagome lattice. The result can be easily generalized to $t-J$ models with antiferromagnetic interactions $J\geq 0$ on the same graphs. This is a weak converse of Nagaoka's theorem of ferromagnetism on a bipartite lattice.Comment: 4 pages + references, a revised versio

Korean American Women\u27s Community Activism and Their Response to Domestic Violence in Philadelphia

Existing standard supportive services for domestic violence in the United States do not adequately address the cultural context for abused Korean immigrant women, and hence, results in further marginalization for this vulnerable population. For decades, Korean American women activists have been constructing support networks in their communities in response to this need. Nonetheless, scholarly literature has failed to capture the work and experiences of Korean American women activists who respond to and address domestic violence in their local community. Therefore, this study aims to give voice to one group of Korean American women activists and illuminate their experiences regarding domestic violence cases. In collaboration with a local Korean American women’s community activists association in one Northeastern U.S. city, this study explores their experiences with two data sources:(1) Korean counseling records of abused Korean immigrant women between 1986-2012, and (2) semi-structured interviews with the activists. Findings presented explicate the experiences of Korean American women activists focused on their response to domestic abuse within their community. This research can be used to guide the development of a model to provide contextually competent support for abused Korean American women in the U.S. and highlights the importance of collaboration between health care providers and ethnic minority community supportive services

Magnon topology and thermal Hall effect in trimerized triangular lattice antiferromagnet

The non-trivial magnon band topology and its consequent responses have been extensively studied in two-dimensional magnetisms. However, the triangular lattice antiferromagnet (TLAF), the best-known frustrated two-dimensional magnet, has received less attention than the closely related Kagome system, because of the spin-chirality cancellation in the umbrella ground state of the undistorted TLAF. In this work, we study the band topology and the thermal Hall effect (THE) of the TLAF with (anti-)trimerization distortion under the external perpendicular magnetic field using the linearized spin wave theory. We show that the spin-chirality cancellation is removed in such case, giving rise to the non-trivial magnon band topology and the finite THE. Moreover, the magnon bands exhibit band topology transitions tuned by the magnetic field. We demonstrate that such transitions are accompanied by the logarithmic divergence of the first derivative of the thermal Hall conductivity. Finally, we examine the above consequences by calculating the THE in the hexagonal manganite YMnO$_3$, well known to have anti-trimerization.Comment: 6 + 7 pages, 3 + 5 figures, 0 + 1 table; Journal reference adde

The widths of quarkonia in quark gluon plasma

Recent lattice calculations showed that the quarkonia will survive beyond the phase transition temperature, and will dissolve at different temperatures depending on the type of the quarkonium. In this work, we calculate the thermal width of the quarkonium at finite temperature before it dissolves into open heavy quarks. The input of the calculation are the parton quarkonium dissociation cross section to NLO in QCD, the quarkonium wave function in a temperature-dependent potential from lattice QCD, and a thermal distribution of partons with thermal masses. We find that for the J/psi, the total thermal width above 1.4 Tc becomes larger than 100 to 250 MeV, depending on the effective thermal masses of the quark and gluon, which we take between 400 to 600 MeV. Such a width corresponds to an effective dissociation cross section by gluons between 1.5 to 3.5 mb and by quarks 1 to 2 mb at 1.4 Tc. However, at similar temperatures, we find a much smaller thermal width and effective cross section for the upsilon.Comment: 7 pages, 13 figures, 2 tables, version to be published in Phys. Rev.

Biological evaluation of 32 different essential oils against Acidovorax citrulli, with a focus on Cinnamomum verum essential oil

Bacterial fruit blotch (BFB) of watermelon caused by Acidovorax citrulli (ACC) is one of the most severe diseases of watermelon worldwide. Antibacterial activity of 32 essential oils (EOs) was evaluated against ACC using disk-diffusion assays. The oil from cinnamon exhibited the greatest antibacterial activity. Using gas chromatography-mass spectrometry (GC-MS), the major components of cinnamon oil were analyzed. Among the various components of cinnamon oil, benzaldehyde and cinnamaldehyde exhibited the effective antibacterial activities against ACC. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of benzaldehyde and cinnamaldehyde were measured using broth dilution assays. The MICs against ACC of benzaldehyde and cinnamaldehyde were 0.1 and 0.01% (v/v), respectively. The MBCs of benzaldehyde and cinnamaldehyde against ACC were 0.2 and 0.02% (v/v), respectively. Also, 0.2% (v/v) levels of cinnamon oil, benzaldehyde and cinnamaldehyde completely killed ACC cells artificially contaminating watermelon seeds. This study suggests that cinnamon oil and its bioactive components, benzaldehyde and cinnamaldehyde, have potential for application as natural agents for the prevention and treatment of BFB.Key words: Acidovorax citrulli, bacterial fruit blotch, cinnamon oil, essential oil