Using high magnetic fields up to 60 T, we report magneto-transport and photoluminescence (PL) studies of a two-dimensional electron gas (2DEG) in a GaN/AlGaN heterojunction grown by molecular-beam epitaxy. Transport measurements demonstrate that the quantum limit can be exceeded (Landau level filling factor ν < 1) and show evidence for the ν = 2 / 3 fractional quantum Hall state. Simultaneous optical and transport measurements reveal synchronous quantum oscillations of both the PL intensity and the longitudinal resistivity in the integer quantum Hall regime.

Physics lab instruction is evolving in response to changing technology, a desire to better prepare students for diverse careers, and renewed focus from physics education researchers. To prepare researchers to evaluate progress in instructional labs in the future, this study set out to understand the current state of instructional physics labs in North America. Using information collected from instructors intending to use two research-based lab assessments, we evaluate the reach, organization, goals, and pedagogies from over 200 unique instructional lab courses at over 100 institutions.

Emergent quantum phenomena in electronically coupled two-dimensional heterostructures are central to next-generation optical, electronic, and quantum information applications. Tailoring electronic band gaps in coupled heterostructures would permit control of such phenomena and is the subject of significant research interest. Two-dimensional polymers (2DPs) offer a compelling route to tailored band structures through the selection of molecular constituents.

A diverse set of SOT materials with vastly different values of spin efficiency, conductivity, and thickness are being explored to achieve the lowest write energy. Research on SOT-assisted STT-MRAM and novel materials for the switching of magnets with perpendicular magnetic anisotropy (PMA) is also ongoing. This paper presents a comprehensive study on the impact of material parameters on array-level read and write operations for both in-plane and PMA MRAM cells. The results offer important guidelines for material development for this technology. © 2020 IEEE.

We report spin-torque ferromagnetic resonance studies of the efficiency of the damping-like (ζDL) spin-orbit torque exerted on an adjacent ferromagnet film by current flowing in epitaxial (001) and (110) IrO2 thin films. IrO2 possesses Dirac nodal lines (DNLs) in the band structure that are gapped by spin-orbit coupling, which could enable a very high spin Hall conductivity, σSH.

Two-dimensional nanoelectronics, plasmonics, and emergent phases require clean and local charge control, calling for layered, crystalline acceptors or donors. Our Raman, photovoltage, and electrical conductance measurements combined with ab initio calculations establish the large work function and narrow bands of α-RuCl3 enable modulation doping of exfoliated single and bilayer graphene, chemical vapor deposition grown graphene and WSe2, and molecular beam epitaxy grown EuS.

The goals for lab instruction are receiving critical attention in the physics education community due to multiple reports and research findings. In this paper, we describe a theoretically motivated scheme to evaluate instructional lab curricula and apply that scheme to three implementations of an electricity and magnetism lab curriculum.

Magnetostriction, coupling between the mechanical and magnetic degrees of freedom, finds a variety of applications in magnetic actuation, transduction and sensing1,2. The discovery of two-dimensional layered magnetic materials3–8 presents a new platform to explore the magnetostriction effects in ultrathin solids. Here we demonstrate an exchange-driven magnetostriction effect in mechanical resonators made of two-dimensional antiferromagnetic CrI3. The mechanical resonance frequency is found to depend on the magnetic state of the material.

Controlling agile and complex air-vehicle maneuvers requires knowledge of the full flight envelope and dominant modes of motion. This paper presents a comprehensive approach for determining the full flight envelope and trim map of minimally actuated flapping-wing micro aerial vehicles that are capable of a broad range of coupled longitudinal–lateral–directional aerobatic maneuvers. By this approach, a representative set of realizable set points and trim conditions can be determined from the flight dynamic model, including asymmetric and unstable maneuvers.

Strong magnetization fluctuations are expected near the thermodynamic critical point of a continuous magnetic phase transition. Such critical fluctuations are highly correlated and in principle can occur at any time and length scales1; they govern critical phenomena and potentially can drive new phases2,3. Although critical phenomena in magnetic materials have been studied using neutron scattering, magnetic a.c. susceptibility and other techniques4–6, direct real-time imaging of critical magnetization fluctuations remains elusive.