Competing Magnetic Orderings and Tunable Topological States in Two-Dimensional Hexagonal Organometallic Lattices

The exploration of topological states is of significant fundamental and practical importance in contemporary condensed matter physics, for which the extension to two-dimensional (2D) organometallic systems is particularly attractive. Using first-principles calculations, we show that a 2D hexagonal triphenyl-lead lattice composed of only main group elements is susceptible to a magnetic instability, characterized by a considerably more stable antiferromagnetic (AFM) insulating state rather than the topologically nontrivial quantum spin Hall state proposed recently. Even though this AFM phase is topologically trivial, it possesses an intricate emergent degree of freedom, defined by the product of spin and valley indices, leading to Berry curvature-induced spin and valley currents under electron or hole doping. Furthermore, such a trivial band insulator can be tuned into a topologically nontrivial matter by the application of an out-of-plane electric field, which destroys the AFM order, favoring instead ferrimagnetic spin ordering and a quantum anomalous Hall state with a non-zero topological invariant. These findings further enrich our understanding of 2D hexagonal organometallic lattices for potential applications in spintronics and valleytronics.Comment: 9 pages, 8 figure

A Three-Decade Decline in the Homeownership Gender Gap: What Drove the Change, and Where Do We Go from Here?

Over the past 30 years, women have made tremendous gains in closing both the income and the education gaps between them and men, and growth in their homeownership rates has become an important manifestation of these trends. In 1990, there were 15.7 million female-headed homeowner households. By 2019, that number had reached 39.2 million. In contrast, the number of male-headed homeowner households decreased from 44.4 million to 43.1 million.In this report, we examine homeownership by the gender of the household head and how it has changed over the past three decades. Our analysis explores factors narrowing the homeownership gender gap, overall and by race and ethnicity. This narrowing can be attributed mostly to gains in household income, followed closely by the fact that more married women are head of household