Gravitational wave constraints on spatial covariant gravities

Gravitational waveform and polarization from binary black hole inspiral in dynamical Chern-Simons gravity: from generation to propagation

“…Current and future GW observations can constrain these gravitational theories with high accuracy [43][44][45][46][47][48][49][50][51][52]. Some kinds of modified theories, including parity-violating effects, have been studied in recent years [53][54][55][56][57][58][59][60][61][62][63][64][65][66], like Chern-Simons (CS) gravity [26,67] (consisting of dynamical and non-dynamical cases), ghost-free parity-violating theory [68][69][70][71][72], Nieh-Yan modified teleparallel gravity [73,74], parity-violating symmetric teleparallel gravities [75] and the general spatial covariant gravities [31,32,60,61,63,[76][77][78]]. As a typical example, CS theory introduces a coupling term between the pseudo-scalar and Pontryagin density in the Einstein-Hilbert action, which causes the nonconservation of the CS topological current.…”

Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions

“…The previous study shows that such devices can effectively reduce critical switching current. [ 32 ] Section S9, Supporting Information, reveals that the J thr of η > 0 SOT devices remain unaffected by pulse width and damping parameter, unlike η < 0 devices that exhibit increased J thr for higher damping parameters or shorter pulse widths. Even in that region ( η > 0), the magnetization undergoes motion along an uncomplicated and abbreviated trajectory, as shown in Figure 1b.…”

“…Theoretical conjectures further suppose that FLT is crucial in mitigating the J sw . [ 29–32 ] In this context, the realization of high‐performance SOT‐based TRNGs necessitates the development of predominant material structures influenced by FLT and mandates a systematic investigation into their consequential effects. Moreover, it remains imperative to ascertain the durability of the underlying physical mechanisms that give rise to random number generation.…”

Deterministic Magnetic Switching in Perpendicular Magnetic Trilayers Through Sunlight‐Induced Photoelectron Injection

“…[ 1–10 ] Spin‐polarized current originated from spin‐transfer torque (STT) in spin‐valves and magnetic tunnel junctions (MTJ) or spin–orbital torque (SOT) at ferromagnetic (FM)/heavy metal (HM) interfaces, is widely used to realize deterministic magnetization switching, ultrafast FM domain wall motion, and GHz FM oscillations in various FM heterostructures. [ 2,3,11–20 ] Researchers devoted a great deal of effort to increasing the charge‐to‐spin conversion rate and reducing energy consumption by developing novel spin‐polarized current generators, such as 2D materials, topological insulators, etc., and optimizing their interfaces. [ 21–30 ] Still, the current density is relatively high, creating localized heat problems, and limiting the storage density and magnetization switching speed.…”