Dynamics of entanglement entropy of interacting fermions in a 1D driven harmonic trap

Following up on a recent analysis of two cold atoms in a time-dependent harmonic trap in one dimension, we explore the entanglement entropy of two and three fermions in the same situation when driven through a parametric resonance. We find that the presence of such a resonance in the two-particle system leaves a clear imprint on the entanglement entropy. We show how the signal is modified by attractive and repulsive contact interactions, and how it remains present for the three-particle system. Additionaly, we extend the work of recent experiments to demonstrate how restricting observation to a limited subsystem gives rise to locally thermal behavior.Comment: Proceedings of Lattice2017, Granada, Spai

Identifying plant cell wall remnants in detritus of a subtropical wetland with fluorescence labeling

Sediment accretion in wetlands represents a significant carbon burial pathway. While litter studies can quantify the loss rates of plant leaf material, those studies do not provide insight into the specific cell wall polymers being retained or lost within the detrital matrix. The Everglades ecosystem has been dramatically altered due to anthropogenic eutrophication and hydrologic modifications. The results are changes in macrophyte species composition and sediment accretion- and loss- rates. To improve ecological conditions, active management strategies are re-establishing open water slough environments. A question remains about the persistence of new- and old- plant cell wall material in sediments because of active management. In this pilot project we utilized immuno-fluorescence labeling with lectins applied to plant leaf material and detrital flocculent collected from created open and control plots in the Everglades to observe the presence, absence, and overlap of specific cell wall polymers between macrophytes and detrital flocculent in increasingly recalcitrant materials that would most likely contribute to peat accumulation. The persistence and loss of specific polymers between treatment and control plots provided insight into the differing levels of recalcitrance amongst plant cell walls and their relative potential as a carbon sink. This study provides a novel method for testing for the presence and persistence of specific cell wall polymers in detritus to gain a better understanding of plant material persistence in wetland ecosystems

Belonging to a research-practice partnership:Lessons from 15 think-pieces about the COVID-19 pandemic and a call for action

Research-Practice Partnerships (RPPs) in education have been gaining increasing currency and support since well before the advent of COVID-19. This article reflects on what the pandemic experience has meant for some RPPs so far, and imagines what other RPPs might look like in the near future. The authors share a collection of fifteen think-pieces written by individuals working in or around, or funding RPPs during the COVID crisis. These contributions include reflections on how the pandemic affected existing RPPs and how teams responded to the disruptions, how the larger context in which RPPs operate matters, as well as how RPPs can help us build a more just and united society. The authors identify lessons to be drawn from across these think-pieces and implications for the field, and close with a call for action about learning scientists’ possibilities for belonging to RPPs. Through a somewhat unconventional form of scholarship, this article intends to spark and enrich conversations about tensions and choices facing RPPs and learning sciences scholarship broadly in the coming years.</p

Virial coefficients of trapped and un-trapped three-component fermions with three-body forces in arbitrary spatial dimensions

Using a coarse temporal lattice approximation, we calculate the first few terms of the virial expansion of a three-species fermion system with a three-body contact interaction in $d$ spatial dimensions, both in homogeneous space as well as in a harmonic trapping potential of frequency $\omega$. Using the three-body problem to renormalize, we report analytic results for the change in the fourth- and fifth-order virial coefficients $\Delta b_4$ and $\Delta b_5$ as functions of $\Delta b_3$. Additionally, we argue that in the $\omega \to 0$ limit the relationship $b_n^\text{T} = n^{-d/2} b_n$ holds between the trapped (T) and homogeneous coefficients for arbitrary temperature and coupling strength (not merely in scale-invariant regimes). Finally, we point out an exact, universal (coupling- and frequency-independent) relationship between $\Delta b_3^\text{T}$ in 1D with three-body forces and $\Delta b_2^\text{T}$ in 2D with two-body forces.Comment: 7 pages, 2 figure