Deviations from tidal torque theory: Evolution of the halo spin–filament alignment

ABSTRACT The alignment between halo spins and the cosmic web is still poorly understood despite being a widely studied topic. Here, we study this alignment within the context of tidal torque theory (TTT) and deviations from it. To this end, we analyse the evolution of the shape and spin direction of proto-haloes, i.e. of all the volume elements associated to a z = 0 halo, with respect to the present-day filaments. We find that the major axis of proto-haloes undergoes a major change, from being strongly perpendicular to the filament spine in the initial conditions, to being preferentially aligned at the present time. In comparison, the spin orientation shows only a mild evolution: it starts slightly parallel to the filament spine, but the subsequent evolution, up to z ∼ 1, gradually changes its orientation to preferentially perpendicular. In order to analyse these signals in the TTT framework, we split the haloes according to their net spin growth with respect to the median TTT expectation, finding a clear correlation with the spin–filament alignment. At the present time, haloes whose spin grew the most are the ones most perpendicular to the filament spine, while haloes whose spin grew below the median TTT expectation are typically more aligned. The dependence of spin directions on net spin growth is already present in the initial conditions, and gets further modified by late-time, z < 2, evolution. Also, spin directions mildly deviate from the TTT predictions even at high redshift, indicating the need for extensions to the model.

Controllable spin direction in nonmagnetic BX/MX2 (M = Mo or W; X = S, Se and Te) van der Waals heterostructures by switching between the Rashba splitting and valley polarization

Manipulating physical properties using the spin degree of freedom constitutes a major part of modern condensed matter physics and is a key aspect for spintronics devices. Using density functional theory...

Ferroelectric Rashba semiconductors, AgBiP2X6 (X = S, Se and Te), with valley polarization: an avenue towards electric and nonvolatile control of spintronic devices

Coexistence of Rashba-type spin splitting (in-plane spin direction) and band splitting at the K/K′ valleys (out-of-plane spin direction) makes the FRS AgBiP2Te6 monolayer a promising candidate for 2D spin FET and spin/valley Hall effect devices.

The adsorption mechanism and electronic properties of FeO–HNCO clusters

The configurations, electronic and spin of the FeO–HNCO clusters are investigated at PW91 method. The calculated results show that the Fe–O–C–N four-member ring preferred to form the FeO–HNCO cluster and it has higher kinetic stability. The isomer which possesses an Fe–O–C triangle ring has higher kinetic activity. The hybridization of sp orbital of C and N atoms of the FeO–HNCO clusters is stronger. For the lowest-energy FeO–HNCO cluster, the Fe and O atoms have the opposite spin direction.

KINETIC BEHAVIOR OF THE INTERACTION BETWEEN TRICALCIUM SILICATE AND LIQUID PHASE

This paper presents a 2D-simulation of the main stages of the tricalcium silicate hardening which reflects a possible mechanism of radical reactions with regard to the spin state of the interacting particles. The principles of the universal static model are used for 2D-simulation. It is shown that the particle charge determines the ionic mechanism. In this case, the electron spin direction does not affect the reaction process. It is demonstrated that the spin direction is important for the interacting particles.