SEARCH · Engineering Papers
Results for “TWIST”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Demonstration of collinear factorization breaking due to collinear-to-soft Glauber exchanges for a 2 → 3 exclusive process at leading twist
We exhibit an exclusive process, namely the photoproduction of a π 0 γ pair with large invariant mass, which violates collinear factorization. We explicitly demonstrate that this is due to the fact that there exists diagrams with gluon exchange in t channel, contributing at the leading power, for which are . This is caused by the pinching of the contour integration of the plus and minus light-cone components of the Glauber gluon momentum. We argue that this leads to the observed “end pointlike” divergence of the convolution integral at leading order and leading power when collinear factorization is naïvely assumed. Published by the American Physical Society 2025
Moiré Exchange Effect in Twisted WSe 2 /WS 2 Heterobilayer
Moiré superlattices of layered transition metal dichalcogenides are proven to host periodic electron crystals due to strong correlation effects. These electron crystals can also be intertwined with intricate magnetic phenomena. Here, in this Letter, we present our findings on the moiré exchange effect, resulting from the modulation of local magnetic moments by electron crystals within well-aligned WSe 2 /WS 2 heterobilayers. Employing polarization-resolved magneto-optical spectroscopy, we unveil a high-energy excitonic resonance near one hole per moiré unit cell (v=–1), which possesses a giant g factor several times greater than the already very large g factor of the WSe 2 A exciton in this heterostructure. Supported by continuum model calculations, these high-energy states are found to be dark excitons brightened through Umklapp scattering from the moiré mini-Brillouin zone. When the carriers form a Mott insulating state near v=–1, the Coulomb exchange between doped carriers and excitons forms an effective magnetic field with moiré periodicity. This moiré exchange effect gives rise to the observed giant g factor for the excitonic Umklapp state.
Fractional Chern Insulators in Twisted Bilayer MoTe 2 : A Composite Fermion Perspective
Not Available
First-principles electron-phonon interactions and electronic transport in large-angle twisted bilayer graphene
Not provided.
Fractional Chern insulator states in twisted bilayer graphene: An analytical approach
Not Available
Electrical band flattening, valley flux, and superconductivity in twisted trilayer graphene
Not Available
Revisiting the impact of dissipation on time-reversed one-axis-twist quantum-sensing protocols
Not Available
Correlation-Induced Insulating Topological Phases at Charge Neutrality in Twisted Bilayer Graphene
Not Available
Presence of s -Wave Pairing in Josephson Junctions Made of Twisted Ultrathin Bi 2 Sr 2 CaCu 2 O 8 + x Flakes
Not Available
Static metrology of the meter-scale deformable heliostat
This paper describes a heliostat metrology system which is developed based on deflectometry, utilizing a static perforated panel instead of conventional dynamic monitor displays to provide incident rays. The developed method is named static screen deflectometry (SSD). This robust and scalable method is especially valuable for outdoor tests of large reflectors used in concentrating solar-thermal power (CSP) systems. The developed method has been successfully demonstrated on a 2.4 𝑚 × 3.3 𝑚 float glass deformable reflector bent to focus sunlight at 113 𝑚 distance throughout a day. From images obtained from a camera at 50𝑚 distance, the reflector surface was measured to an accuracy of less than 1 𝑚𝑟𝑎𝑑 rms slope error in the full test scope.
Twisted bilayer graphene: topological pumping and switching of topology by current [Slides]
The presentation was prepared for a BLABS seminar and includes various graphical images. The summary given highlighted: Topological pumping can be triggered by interlayer sliding in TBG due to the nontrivial topology associated with the synthetic dimension; Time-reversal symmetry of TBG can be spontaneously broken by Coulomb interaction, that results in the valley-polarized QAH state at 3/4 filling; A large enough current can pump electrons from the valence band to conductance band, that redistributes the electron occupation; and, the redistribution of electron occupation combined with the Coulomb interaction can switch the valley polarization and topology.
Reasons to resist rolling and twisting in granular materials.
Abstract not provided.
Granular rheology with sliding rolling and twisting friction.
Abstract not provided.
Magnetic anisotropy in twisted bilayer graphene and ABC-trilayer graphene aligned with hexagonal boron nitride.
Abstract not provided.