Article
Materials Science, Multidisciplinary
Pierre A. Pantaleon, Tony Low, Francisco Guinea
Summary: Twisted bilayer graphene is highly sensitive to external perturbations, leading to valley currents and nonlinear Hall effect. These effects described by a Berry dipole exhibit high tunability due to their dependence on applied strain, coupling to the substrate, carrier density, and temperature.
Article
Chemistry, Multidisciplinary
Satya N. Guin, Qiunan Xu, Nitesh Kumar, Hsiang-Hsi Kung, Sydney Dufresne, Congcong Le, Praveen Vir, Matteo Michiardi, Tor Pedersen, Sergey Gorovikov, Sergey Zhdanovich, Kaustuv Manna, Gudrun Auffermann, Walter Schnelle, Johannes Gooth, Chandra Shekhar, Andrea Damascelli, Yan Sun, Claudia Felser
Summary: MnAlGe is a unique topological magnet with 2D ferromagnetic layers, nodal-line semimetal properties, and an out-of-plane magnetization at room temperature; the unique 2D distribution of Mn atoms controls its electrical, magnetic, and topological properties.
ADVANCED MATERIALS
(2021)
Article
Physics, Multidisciplinary
Ya-Ning Ren, Qiang Cheng, Qing-Feng Sun, Lin He
Summary: In this study, the valley-polarized energy spectra of graphene quantum dots were achieved by continuously tunable Berry phases through adjusting the magnetic field. The large and continuously tunable valley-polarized energy spectra were realized by altering the Berry phase to noninteger multiples of zero. This research sheds light on graphene-based valleytronics and provides new experimental and theoretical evidence.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Jiawei Wang, Sreeramulu Valligatla, Yin Yin, Lukas Schwarz, Mariana Medina-Sanchez, Stefan Baunack, Ching Hua Lee, Ronny Thomale, Shilong Li, Vladimir M. Fomin, Libo Ma, Oliver G. Schmidt
Summary: The Mobius strip offers a platform for investigating the topological behavior of spinning particles, such as electrons, polaritons, and photons. Despite theoretical investigations, the optical Berry phase in a Mobius-strip cavity has not been experimentally observed until now. In this study, the researchers successfully observed the Berry phase generated in optical Mobius-strip microcavities by generating elliptical polarization of the resonating light.
Article
Physics, Multidisciplinary
Alex Hiro Mayo, Hidefumi Takahashi, Mohammad Saeed Bahramy, Atsuro Nomoto, Hideaki Sakai, Shintaro Ishiwata
Summary: This study investigates the magnetic-field-induced switching of band topology in alpha-EuP3. The results show that a giant anomalous Hall effect signal emerges when the magnetic field is applied perpendicular to the monoclinic structure's single mirror plane. On the other hand, applying the magnetic field along the interlayer direction leads to a pronounced negative longitudinal magnetoresistance. The researchers found that these anomalies are manifestations of two distinct topological phases: topological nodal-line and Weyl semimetals.
Review
Chemistry, Multidisciplinary
Ping Wang, Yang Yang, Er Pan, Fucai Liu, Pulickel M. Ajayan, Jiadong Zhou, Zheng Liu
Summary: This article introduces the unusual phases and characteristics of layered metal chalcogenides, as well as their potential applications. It discusses the methods and strategies for producing the unusual phases and provides an outlook on the synthetic methodology and potential applications.
Article
Physics, Multidisciplinary
Sameer Grover, Matan Bocarsly, Aviram Uri, Petr Stepanov, Giorgio Di Battista, Indranil Roy, Jiewen Xiao, Alexander Y. Meltzer, Yuri Myasoedov, Keshav Pareek, Kenji Watanabe, Takashi Taniguchi, Binghai Yan, Ady Stern, Erez Berg, Dmitri K. Efetov, Eli Zeldov
Summary: Using a scanning superconducting quantum interference device on a tip, a spatial patchwork of different Chern insulator states in twisted bilayer graphene is imaged. The nanoscale equilibrium orbital magnetism induced by the Berry curvature is detected, along with its two constituent components.
Article
Materials Science, Multidisciplinary
Zhan Gao, Yan He
Summary: This study investigates the time evolution of geometric phases in one-dimensional topological models under quench dynamics. It is found that the Berry phase remains fixed when the parameter suddenly crosses the topological phase boundary, as long as the inversion symmetry of the model is preserved. At finite temperature, the Uhlmann phase exhibits abrupt jumps between two quantized values, indicating topological transitions at certain times after the quench. Both the Berry and Uhlmann phases deviate from quantized values if the inversion symmetry of the model is broken.
Article
Multidisciplinary Sciences
Lukas Powalla, Jonas Kiemle, Elio J. Koenig, Andreas P. Schnyder, Johannes Knolle, Klaus Kern, Alexander Holleitner, Christoph Kastl, Marko Burghard
Summary: Researchers have discovered local tunable spin polarization in current-driven graphene/WTe2 heterostructures using magneto-optical Kerr microscopy. They have presented a theoretical model explaining the spatial distribution of the Kerr signal and revealed the significant potential of 2D heterostructures for spintronics.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Jie Liu, Lin Wang, Ka Shen
Summary: The introduction of effective spin-orbit couplings into magnon systems opens up possibilities to explore novel and intriguing topological phases. In this study, we theoretically investigate the magnon spin-orbit coupling in a layered collinear easy-axis ferrimagnet with dipole-dipole interaction and antiferromagnetic interlayer exchange coupling. We predict the existence of a nodal-loop semimetal phase in the perpendicular magnetization geometry and a Weyl semimetal phase in the lateral magnetization geometry. Additionally, we demonstrate the transformation of the nodal loop into two Weyl points in a noncollinear spin configuration by applying a perpendicular magnetic field. Our findings reveal the significance of noncollinear spin texture in magnon topology and contribute to the study of topological ferrimagnonics.
Article
Chemistry, Multidisciplinary
Seo-Jin Kim, Jihang Zhu, Mario M. Piva, Marcus Schmidt, Dorsa Fartab, Andrew P. Mackenzie, Michael Baenitz, Michael Nicklas, Helge Rosner, Ashley M. Cook, Rafael Gonzalez-Hernandez, Libor Smejkal, Haijing Zhang
Summary: A spontaneous anomalous Hall effect is observed in a layered polar semiconductor, and remarkably, the magnitude of the anomalous Hall conductivity can be enhanced by tuning the carrier density employing ionic-gated transistors. Theoretical calculations, considering the magnetic order and polar nature, align well with experimental observations. The findings shed new light on exploring the interplay between magnetic and polar structures.
Article
Materials Science, Multidisciplinary
H. S. Vishwanath, M. P. Shilpa, S. C. Gurumurthy, Murali Gedda, Koduri Ramam, K. M. Eshwarappa, Ravi Kirana, Nirankar Nath Mishra, Shridhar Mundinamani
Summary: Textile and clothing industry effluents are a major source of water pollution, and it is important to filter these effluents to prevent contamination. This study introduces the use of carbon-based membranes coated with graphene oxide (GO) and reduced graphene oxide (RGO) on cellulose surfaces for efficient dye filtration. The results show high filtration rates of 98% and 94% for methylene blue and rose bengal dyes, respectively, making it an eco-friendly method for treating industrial dye-contaminated water.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Physics, Particles & Fields
Souvik Banerjee, Moritz Dorband, Johanna Erdmenger, Rene Meyer, Anna-Lena Weigel
Summary: In this study of two-dimensional holographic conformal field theories (CFTs), we investigate the role of Berry phases in relating the non-factorization of the Hilbert space to the presence of wormholes. We find that the wormholes are characterized by a non-exact symplectic form, which induces the occurrence of Berry phases. Specifically, for wormholes connecting spacelike regions in gravitational spacetimes, the non-exactness is linked to a variable in the phase space of the boundary CFT, corresponding to a loop integral in the bulk. This leads to non-factorization in the dual entangled CFTs. Additionally, we classify Berry phases in holographic CFTs based on the type of dual bulk diffeomorphism involved, distinguishing between Virasoro, gauge, and modular Berry phases, each associated with a spacetime wormhole geometry in the bulk. Moreover, we extend the relation between the modular Hamiltonian and the Berry curvature to the finite temperature case using kinematic space, where the Crofton form characterizes the topological transition of the entanglement entropy in the presence of a black hole.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Xiaosong Liu, Zehong Yan, Enlin Wang, Xiaofei Zhao, Tianling Zhang, Fangfang Fan
Summary: This letter presents a bifunctional full-space metasurface (FS-MS) capable of generating reflective multiple vortex beams and focusing transmissive electromagnetic waves within different frequency bands. The generation of vortex beams is achieved by rotating the orientation angle of an I-shaped patch based on the Pancharatnam-Berry (PB) phase. A metallic square loop frequency selective surface (FSS) is used to support the PB unit, which allows the generation of reflective vortex beams at a higher frequency band. At a lower frequency band, the incident waves can pass through the FSS-backed PB unit and be focused by a three-layer composite unit. The proposed FS-MS can function as a multiple OAM beams generator and a focusing lens simultaneously.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Physics, Multidisciplinary
Robert J. Ducharme, Irismar G. da Paz, Armen G. Hayrapetyan
Summary: A new Bateman-Hillion solution for relativistic Gaussian electron beams in the Dirac equation is presented, which considers the four-position of the beam waist. The solution contains higher order Laguerre-Gaussian components beyond the paraxial limit due to tighter focusing. The study shows that the mixed mode nature of strongly diffracting beams leads to fractional expectation values for spin and orbital angular momenta, which are interrelated and can be expressed by means of Berry phase.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Armin Tavakoli, Massimiliano Smania, Tamas Vertesi, Nicolas Brunner, Mohamed Bourennane
Article
Physics, Multidisciplinary
Geza Toth, Tamas Vertesi, Pawel Horodecki, Ryszard Horodecki
PHYSICAL REVIEW LETTERS
(2020)
Article
Quantum Science & Technology
Artur Barasinski, Antonin Cernoch, Wieslaw Laskowski, Karel Lemr, Tamas Vertesi, Jan Soubusta
Summary: This study investigates an operational measure of nonlocality proposed by Fonseca and Parisio, examining the probability and strength of violating local realism, and suggests a simple experimental procedure for determining these quantities for N-qubit pure states. The research shows that even with randomly selected pure states and measurement bases, experimental detection of violations of local realism is almost guaranteed.
Article
Quantum Science & Technology
Pei-Sheng Lin, Tamas Vertesi, Yeong-Cherng Liang
Summary: Through numerical estimation of various Bell scenarios, we observe the volume changes between the quantum correlations set and the nonsignaling correlations set, noting that in some cases the quantum set can be well approximated by other subsets, while significant differences exist in others.
Article
Physics, Multidisciplinary
Mahasweta Pandit, Artur Barasinski, Istvan Marton, Tamas Vertesi, Wieslaw Laskowski
Summary: This paper proposes an optimal and efficient numerical test for witnessing genuine multipartite nonlocality based on a geometric approach. It applies general tests to detect and characterize genuine n-way nonlocal correlations for various quantum systems. The paper also explores the extension of measurements beyond two and proposes a simple procedure to detect nonlocal correlations with high efficiency.
NEW JOURNAL OF PHYSICS
(2022)
Article
Quantum Science & Technology
Karoly F. Pal, Tamas Vertesi
Summary: This paper investigates the Platonic Bell inequalities in different dimensions. For three-dimensional Platonic solids, measurement directions point towards the vertices, while in higher dimensions, measurements are associated with the abstract Tsirelson space. The paper provides a simple formula for the quantum violation of all Platonic Bell inequalities, proving that the maximum quantum violation is achieved. Additionally, the paper presents an efficient method for computing the local bound of Bell inequalities with a large number of settings, and demonstrates its practicality through specific examples.
Article
Physics, Multidisciplinary
Istvan Marton, Sandor Nagy, Erika Bene, Tamas Vertesi
Summary: This study generalizes the EPR steering phenomenon to three parties, finding a cyclic property of tripartite EPR steering, and identifies a three-qubit state with this property.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Physics, Multidisciplinary
Karoly F. Pal, Geza Toth, Erika Bene, Tamas Vertesi
Summary: In this paper, two classes of PPT entangled states for any dimension d >= 2 are presented, which outperform all separable states significantly in metrology. It is shown that these states provide the maximal metrological gain achievable by PPT states for a given system size, and reach a maximal metrological gain equal to a pair of maximally entangled qubits as the dimension d goes to infinity. Therefore, these states could be considered as PPT singlets.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Optics
Anna de Rosier, Jacek Gruca, Fernando Parisio, Tamas Vertesi, Wieslaw Laskowski
Article
Optics
Waldemar Klobus, Adam Burchardt, Adrian Kolodziejski, Mahasweta Pandit, Tamas Vertesi, Karol Zyczkowski, Wieslaw Laskowski
Article
Optics
Karoly F. Pal, Tamas Vertesi
Article
Physics, Multidisciplinary
Pawel Kurzynski, Wieslaw Laskowski, Adrian Kolodziejski, Karoly F. Pal, Junghee Ryu, Tamas Vertesi
COMMUNICATIONS PHYSICS
(2019)
Article
Optics
Armin Tavakoli, Jedrzej Kaniewski, Tamas Vertesi, Denis Rosset, Nicolas Brunner
Article
Optics
Alejandro Fonseca, Anna de Rosier, Tamas Vertesi, Wieslaw Laskowski, Fernando Parisio
Article
Optics
Kamil Kostrzewa, Wieslaw Laskowski, Tamas Vertesi
