Article
Astronomy & Astrophysics
Tomonori Inoue, Makoto Sakamoto, Masatoshi Sato, Inori Ueba
Summary: This paper investigates the properties of five-dimensional Dirac fermions on quantum graphs, providing a complete topological classification of boundary conditions in terms of noninteracting fermionic topological phases. The study identifies ten symmetry classes of topological phases and gives topological numbers of the boundary conditions, predicting the presence of four-dimensional massless fermions localized at the vertex of the quantum graphs, which govern the low energy physics in four dimensions.
Article
Astronomy & Astrophysics
Camille Bonvin, Levon Pogosian
Summary: Our current observations cannot distinguish between models with a fifth force acting on dark matter and those with modified laws of gravity. However, future gravitational redshift data may provide a solution. Alternative gravity theories typically include additional degrees of freedom that can mediate forces between matter particles. A fifth force in these theories can be detected through a gravitational slip, while a dark sector interaction does not cause such a slip. By measuring the effective gravitational slip through cosmological surveys, we can determine if dark matter is affected by a fifth force or modified gravity. Future observations of gravitational redshift can provide a direct measurement of time distortion and help resolve this question.
Article
Physics, Particles & Fields
Claudio Coriano, Matteo Maria Maglio, Dimosthenis Theofilopoulos
Summary: This study investigates the gravitational backreaction generated by coupling a general conformal sector to external, classical gravity, and discusses the regularization of topological Gauss-Bonnet and Weyl terms in these actions. It also explores both local and nonlocal expressions of these theories and shows possible conclusions for nonlocal EGB theories.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Chemistry, Physical
Yu-Chen Wang, Yi Zhao
Summary: A new diagrammatic quantum Monte Carlo approach is proposed to deal with the imaginary time propagator involving both dynamic and static disorder, and can efficiently evaluate various physical quantities.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Akira Matsui, Takuya Nomoto, Ryotaro Arita
Summary: Motivated by recent findings on short-pitch skyrmion lattices, this study investigates the skyrmion-size dependence of the topological Hall effect. The Hall conductivity reaches its extreme value in the crossover region where both real-space and momentum-space Berry curvature are crucial. The optimum skyrmion size lambda(sk)*, separating different regions, is found to be less sensitive to the lifetime of itinerant electrons and coupling constant between electrons and localized spins compared to conventional expectations.
Article
Clinical Neurology
Yaomin Guo, Kangqiang Peng, Ying Liu, Linchang Zhong, Chao Dang, Zhicong Yan, Ying Wang, Jinsheng Zeng, Weixi Zhang, Zilin Ou, Gang Liu
Summary: Large-scale white matter structural networks in patients with blepharospasm undergo extensive reorganization, characterized by alterations in network integration and segregation, increased efficiency in multiple cortical and subcortical regions, and distinct hub distribution patterns. These changes may be due to both dystonia-specific abnormalities and facial hyperkinetic movements.
MOVEMENT DISORDERS
(2021)
Article
Mathematics
Antonio Aviles, Gonzalo Martinez-Cervantes, Jose Rodriguez, Abraham Rueda Zoca
Summary: This paper analyzes different properties of Banach spaces such as Corson's property, weakly Lindelof determined, weakly compactly generated, and Hilbert generated spaces, and provides some conclusions and properties.
JOURNAL OF FUNCTIONAL ANALYSIS
(2022)
Article
Neurosciences
Jiaojian Wang, Zhengbo Wang, Hongjiang Zhang, Shufei Feng, Yi Lu, Shuang Wang, Hong Wang, Yi Eve Sun, Yongchang Chen
Summary: The study revealed that the brain white matter microstructure of Rett syndrome monkey models was initially disrupted but recovered later on, while the white matter network topology showed persistent abnormal dynamics, which were closely related to the behavioral abnormalities associated with RTT.
Article
Clinical Neurology
Ye Tu, Jihong Wang, Zheng Li, Fei Xiong, Feng Gao
Summary: This study revealed disrupted whole-brain structural connectivity in fibromyalgia (FM), leading to compromised neural integration and segregation.
Article
Physics, Multidisciplinary
S. Klevtsov, D. Zvonkine
Summary: This study generalizes the flux insertion argument to the case of fractional quantum Hall states on a higher-genus surface, and applies this test to investigate the robustness and topologicity of Laughlin states. The results show that Laughlin states with localized quasiholes have precisely quantized Hall current, while Laughlin states with nonlocalized quasiholes are not projectively flat.
PHYSICAL REVIEW LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Jiang Liu, Felix Kerner, Nicolas Schlueter, Daniel Schroeder
Summary: This study investigates the factors influencing the performance of polymer electrolyte membrane (PEM) electrolyzers, specifically the porous transport layer (PTL). By conducting numerical simulations and calculations, the researchers found that reducing porosity and fiber radii improved interfacial contact and electrical conductivity of the PTL, while decreasing the anisotropy parameters increased electrical conductivity in the through-plane direction. The design of PTLs should be differentiated based on the operating conditions, with lower porosity and fiber radii for nonstarvation conditions and higher porosity, lower anisotropy parameters, and smaller fiber radii for starvation conditions. Graded PTLs with customized porosity, fiber radius, and fiber orientation can enhance structural and transport properties.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Psychiatry
Yun Cai, Jinghui Zhao, Lian Wang, Yuanjun Xie, Xiaotang Fan
Summary: Research has found that there are abnormalities in the topological organization of the white matter structural network in adults with autism spectrum disorder (ASD), which may play a crucial role in the underlying pathological mechanism of ASD.
ASIAN JOURNAL OF PSYCHIATRY
(2022)
Article
Neurosciences
Yan Zou, Hui Ma, Bo Liu, Dan Li, Dingxi Liu, Xinrong Wang, Siqi Wang, Wenliang Fan, Ping Han
Summary: This study found that SSNHL patients showed decreased global network integration and segregation, reflected by decreased clustering coefficient, local efficiency, global efficiency, normalized clustering coefficient, normalized characteristic path length, and small-worldness, along with increased characteristic path length compared to healthy controls. Nodal centralities in specific brain regions associated with various networks were also altered in SSNHL patients.
FRONTIERS IN NEUROSCIENCE
(2021)
Article
Mathematics, Applied
Sang-Eon Han
Summary: This article translates the importance of MW-topological spaces and proves that they satisfy the semi-T-3 separation axiom. By proposing several techniques, the article distinguishes between the semi-openness and semi-closedness of sets in MW-topological spaces and proves some important properties.
Article
Biochemistry & Molecular Biology
Hamidreza Ghafouri, Tamas Lazar, Alessio Del Conte, Luiggi G. Tenorio Ku, Silvio C. E. PED Consortium, Peter Tompa, Silvio C. E. Tosatto, Alexander Miguel Monzon
Summary: The Protein Ensemble Database is a primary resource for storing structural ensembles of intrinsically disordered proteins. The updated version reflects advancements in the field and includes new features to improve the accessibility and usability of the database.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Chemistry, Physical
T. Pandey, L. Covaci, F. M. Peeters
Summary: This study explores the flexoelectric and electronic properties of zig-zag graphene nanoribbons under mechanical bending using state of the art first principles calculations. The flexoelectric properties of graphene nanoribbons can be significantly improved by hydrogen and fluorine functionalization, with a large flexoelectric effect predicted for CF nanoribbons. Bending can also control the charge localization of valence band maxima, enabling the tuning of hole effective masses and band gaps.
Review
Physics, Multidisciplinary
Zheyong Fan, Jose H. Garcia, Aron W. Cummings, Jose Eduardo Barrios-Vargas, Michel Panhans, Ari Harju, Frank Ortmann, Stephan Roche
Summary: In recent years, predictive computational modeling has become crucial in studying fundamental electronic, optical, and thermal properties in complex condensed matter. Linear scaling numerical methods have been developed to simulate quantum transport in realistic models, and have been used extensively to explore quantum transport phenomena in disordered media. The review also addresses the trade-off between computational cost and accuracy of different numerical schemes, and demonstrates the usefulness of these methods through examples in the study of transport in disordered materials.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
I. R. Lavor, D. R. da Costa, L. Covaci, M. V. Milosevic, F. M. Peeters, A. Chaves
Summary: The study reveals that moire excitons in heterobilayers exhibit a band structure similar to Dirac-Weyl fermions and demonstrate Zitterbewegung motion on long timescales, providing an advantageous solid-state platform for exploring Zitterbewegung.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Armando Pezo, Zeila Zanolli, Nils Wittemeier, Pablo Ordejon, Adalberto Fazzio, Stephan Roche, Jose H. Garcia
Summary: Proximity effects between layered materials lead to novel quantum transport phenomena, and the nature and strength of these effects can be modulated by changing crystalline and interfacial symmetries, providing opportunities for optimizing physical properties relevant for innovative applications.
Article
Materials Science, Multidisciplinary
Andrey Chaves, Lucian Covaci, Francois M. Peeters, Milorad Milosevic
Summary: In a twisted van der Waals heterostructure, a twin boundary separates regions with nearly opposite inter-layer twist angles. In a MoS2/WSe2 bilayer, topologically protected chiral moire exciton states are confined at the twist boundary, which are one-dimensional and uni-directional excitons composed of electronic states with opposite valley/spin character, enabling intrinsic, guided, and far-reaching valley-polarized exciton currents.
Article
Nanoscience & Nanotechnology
Regina Galceran, Bo Tian, Junzhu Li, Frederic Bonell, Matthieu Jamet, Celine Vergnaud, Alain Marty, Jose H. Garcia, Juan F. Sierra, Marius Costache, Stephan Roche, Sergio O. Valenzuela, Aurelien Manchon, Xixiang Zhang, Udo Schwingenschlogl
Summary: The interconversion between spin and charge degrees of freedom in van der Waals materials offers incredible potential for spintronic devices, especially with the emergence of materials possessing large spin-orbit coupling and layered ferromagnets. There is abundant room for progress in discovering and analyzing novel spin-charge interconversion phenomena, as well as exploring modifying properties through proximity effects. Recent advances in techniques for large-scale growth, device physics, and theoretical aspects have significantly contributed to the field.
Article
Materials Science, Multidisciplinary
Jose H. Garcia, Jinxuan You, Monica Garcia-Mota, Peter Koval, Pablo Ordejon, Ramon Cuadrado, Matthieu J. Verstraete, Zeila Zanolli, Stephan Roche
Summary: We have demonstrated the possibility of coherent electrical manipulation of spin orientation in a low-symmetry quantum spin Hall insulator. The spin textures of edge currents can be efficiently varied by small electric fields without affecting their topological character. These findings are important for the development of gate-controllable spin-based devices with topological protection.
Article
Materials Science, Multidisciplinary
Tarik P. Cysne, Sayantika Bhowal, Giovanni Vignale, Tatiana G. Rappoport
Summary: The study of the orbital Hall effect in bilayers of transition metal dichalcogenides provides insights into the interlayer coupling and the role of different descriptions of the orbital angular momentum operator in understanding this phenomenon. The results support recent theoretical predictions on OHE in two-dimensional materials.
Article
Materials Science, Multidisciplinary
Shahid Sattar, J. Andreas Larsson, C. M. Canali, Stephan Roche, Jose H. Garcia
Summary: We demonstrate the presence of significant magnetism and valley polarization in Janus Pt dichalcogenides when bound to a EuO substrate. This proximity-induced effect leads to the formation of two valleys in the conduction bands, each with its own spin polarization and specific spin texture.
Review
Physics, Applied
Hidekazu Kurebayashi, Jose H. Garcia, Safe Khan, Jairo Sinova, Stephan Roche
Summary: This review focuses on the spintronic properties of layered materials and emphasizes the importance of optimizing chemical interactions and material symmetries to achieve the best performing material design for spin-orbit torque efficiency.
NATURE REVIEWS PHYSICS
(2022)
Article
Physics, Multidisciplinary
Marc Vila, Chuang-Han Hsu, Jose H. Garcia, L. Antonio Benitez, Xavier Waintal, Sergio O. Valenzuela, Vitor M. Pereira, Stephan Roche
Summary: This study reveals a novel canted spin Hall effect in few-layer MoTe2 and WTe2 materials, characterized by in-plane and out-of-plane spin polarizations. The decreased symmetry of these materials leads to a large gate-tunable figure of merit for the spin Hall effect, showing potential for applications in spintronic devices.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Marc Vila, Jose H. Garcia, Stephan Roche
Summary: This study demonstrates the realization and control of a fully valley-polarized quantum anomalous Hall effect in bilayer graphene by separately imprinting spin-orbit and magnetic proximity effects in different layers. The topological phase can be controlled by a gate voltage and switched between valleys by reversing the sign of the exchange interaction. Quantum transport calculations show the chirality and resilience of the valley-polarized edge state.
Article
Materials Science, Multidisciplinary
Idris Smaili, Slimane Laref, Jose H. Garcia, Udo Schwingenschlogl, Stephan Roche, Aurelien Manchon
Summary: Theoretical predictions suggest that vanadium-based Janus dichalcogenide monolayers are an ideal platform for spin-orbit torque memories. First-principles calculations show that the magnetic exchange and anisotropy energies are higher for heavier chalcogen atoms, with the Janus structure leading to the emergence of Rashba-like spin-orbit coupling. The efficiency of spin-orbit torque is comparable to heavy nonmagnetic metals, and the coexistence of magnetism and spin-orbit coupling in these materials opens up new possibilities for nonvolatile magnetic random access memories.
Article
Materials Science, Multidisciplinary
Thomas Aktor, Jose H. Garcia, Stephan Roche, Antti-Pekka Jauho, Stephen R. Power
Summary: This study reports the emergence of bulk, valley-polarized currents in graphene-based devices, driven by spatially varying regions of broken sublattice symmetry, and identified by nonlocal resistance fingerprints. These features are robust against disorder and provide a plausible interpretation of controversial experiments in graphene/hexagonal boron nitride superlattices. The findings suggest an alternative mechanism for the generation of valley Hall effect in graphene and a route towards valley-dependent electron optics through materials and device engineering.
Article
Materials Science, Multidisciplinary
Tarik P. Cysne, Filipe S. M. Guimaraes, Luis M. Canonico, Tatiana G. Rappoport, R. B. Muniz
Summary: The study investigates the profiles of spin and orbital angular momentum accumulations induced by a longitudinally applied electric field in nanoribbons with a honeycomb lattice structure. It is found that nanoribbons with zigzag borders may exhibit orbital magnetoelectric effects, and purely orbital magnetization oriented perpendicularly to the ribbon can be induced by the external electric field when sublattice symmetry is broken. This effect is quite general and may also occur in other multiorbital materials.
