Exploring diverse students’ negotiation of lab roles through positioning
Prior work has found inequities in what experimental roles students take on during instructional labs. Research also suggests that this role division might arise implicitly and that prompting explicit role negotiation might improve equity in lab group work. To understand these various ways students negotiate roles in their lab groups, we use the lens of positioning to analyze two different video episodes of a gender-and-race-diverse group of three students.
Machine learning for automated content analysis: characteristics of training data impact reliability
Natural language processing (NLP) has the capacity to increase the scale and efficiency of content analysis in Physics Education Research. One promise of this approach is the possibility of implementing coding schemes on large data sets taken from diverse contexts. Applying NLP has two main challenges, however. First, a large initial human-coded data set is needed for training, though it is not immediately clear how much training data are needed. Second, if new data are taken from a different context from the training data, automated coding may be impacted in unpredictable ways.
So Unfair it’s Fair: Equipment handling in remote versus in-person introductory physics labs
While understanding laboratory equipment is an important learning goal of physics laboratory (lab) instruction, previous studies have found inequities as to who gets to use equipment in in-person lab classes. With the transition to remote learning during the COVID-19 pandemic, class dynamics changed and the effects on equipment usage remain unclear. As part of a larger effort to make intro physics labs more equitable, we investigated student equipment usage based on gender and race in two introductory physics lab courses, one taught in-person and one taught remotely.
Student views of what counts as doing physics in the lab
Numerous studies have identified gender inequity in how students divide roles in lab courses. Few studies, however, have probed how these inequities impact women’s experimental physics identity development. In this work, we used closed-response surveys to investigate which lab tasks students view as part of “doing physics” and how these designations varied by gender. In both courses, we found that most students viewed working with the experimental apparatus, taking lab notes, doing data analysis, and thinking about the physics theory behind the experiment as part of doing physics.
Students’ varying responses to instructor prompts for frame shifts in physics labs
Research has shown that students in inquiry-based physics labs often expect their experiment to verify a known theory or model, contrary to the goals of the lab. It is important, therefore, to identify ways for instructors to shift students’ expectations or epistemic frames to those in line with scientific inquiry. In this paper, we analyze video recordings of one inquiry-based lab session in which the instructor intentionally encourages students to falsify, or disprove, the claim under investigation.
Microscopic robots with onboard digital control
Autonomous robots-systems where mechanical actuators are guided through a series of states by information processing units to perform a predesigned function-are expected to revolutionize everything from health care to transportation. Microscopic robots are poised for a similar revolution in fields from medicine to environmental remediation. A key hurdle to developing these microscopic robots is the integration of information systems, particularly electronics fabricated at commercial foundries, with microactuators.
Author Correction: Tilted spin current generated by the collinear antiferromagnet ruthenium dioxide
In the version of this article initially published, the title of Fig. 2b was incorrectly shown as “(101) RuO2/Py” where it should have been “(001) RuO2/Py.” An expression in Fig. 3b was incorrectly shown as (Formula presented.) where it should have been (Formula presented.). The changes have been made to the HTML and PDF versions of the article. © The Author(s), under exclusive licence to Springer Nature Limited 2022.
Gate-Tunable Anomalous Hall Effect in a 3D Topological Insulator/2D Magnet van der Waals Heterostructure
We demonstrate advantages of samples made by mechanical stacking of exfoliated van der Waals materials for controlling the topological surface state of a three-dimensional topological insulator (TI) via interaction with an adjacent magnet layer. We assemble bilayers with pristine interfaces using exfoliated flakes of the TI BiSbTeSe2and the magnet Cr2Ge2Te6, thereby avoiding problems caused by interdiffusion that can affect interfaces made by top-down deposition methods. The samples exhibit an anomalous Hall effect (AHE) with abrupt hysteretic switching.
Sachdev-Ye-Kitaev models and beyond: Window into non-Fermi liquids
This is a review of the Sachdev-Ye-Kitaev (SYK) model of compressible quantum many-body systems without quasiparticle excitations, and its connections to various theoretical studies of non-Fermi liquids in condensed matter physics. The review is placed in the context of numerous experimental observations on correlated electron materials. Strong correlations in metals are often associated with their proximity to a Mott transition to an insulator created by the local Coulomb repulsion between the electrons.
On the electron pairing mechanism of copper-oxide high temperature superconductivity
The elementary CuO2 plane sustaining cuprate high-temperature superconductivity occurs typically at the base of a periodic array of edge-sharing CuO5 pyramids. Virtual transitions of electrons between adjacent planar Cu and O atoms, occurring at a rate t/Ì„h and across the charge-transfer energy gap â„‡, generate â€œsuperexchangeâ€ spinâ€“spin interactions of energy J â‰ˆ 4t4=â„‡3 in an antiferromagnetic correlated-insulator state. However, hole doping this CuO2 plane converts this into a very-high-temperature superconducting state whose electron pairing is exceptional.