Article
Materials Science, Multidisciplinary
A. V. Kapranov, R. S. Akzyanov, A. L. Rakhmanov
Summary: We study different types of vortices in a topological superconductor with nematic superconductivity in the Eu representation, including the Abrikosov vortex associated with vorticity in the particle-hole space and the spin vortex associated with vorticity in the spin space. By deriving the free energy using the Ginzburg-Landau approach, we calculate the critical strain at which the spin vortex is formed and show that the spin vortex and the Abrikosov vortex attract each other, resulting in a common core. We also apply Bogoliubov-de Gennes equations to study electronic states in a combined vortex structure and find no zero-energy states localized near the common vortex core of any type of vortex.
Article
Materials Science, Multidisciplinary
S. Sajad Dabiri, Hosein Cheraghchi, Ali Sadeghi
Summary: The study examines the photon-dressed electronic band structure of topological insulator thin films doped by magnetic impurities under the influence of off-resonance time-periodic electromagnetic field. Different phases emerge in the phase diagram depending on the frequency, intensity, and polarization of the light. The existence of quantum anomalous Hall insulator and quantum pseudo-spin Hall insulator phases, as well as anisotropic helical edge states, are confirmed through numerical calculations and analysis of the Hall conductivity and Chern number.
Article
Chemistry, Multidisciplinary
Peng Li, Jinjun Ding, Steven S-L Zhang, James Kally, Timothy Pillsbury, Olle G. Heinonen, Gaurab Rimal, Chong Bi, August DeMann, Stuart B. Field, Weigang Wang, Jinke Tang, Jidong Samuel Jiang, Axel Hoffmann, Nitin Samarth, Mingzhong Wu
Summary: This study reports a genuine topological Hall effect in a TI/MI structure, where the contribution of skyrmions to the Hall effect outweighs the coexistence of magnetic phases.
Article
Physics, Multidisciplinary
Ruochen Ma, Chong Wang
Summary: In this study, we demonstrate that symmetry-protected topological (SPT) phases can also be applied to average symmetries, where local quenched disorders break the symmetries but restore them upon disorder averaging. We classify and characterize a large class of average SPT phases using a decorated domain wall approach, and show that the boundary states of such phases will almost certainly be long-range entangled. We also develop a theory for generalized average SPT phases based on density matrices and quantum channels, indicating that topological quantum phenomena associated with average symmetries can be as rich as those with exact symmetries.
Article
Physics, Multidisciplinary
Yafei Ren, Cong Xiao, Daniyar Saparov, Qian Niu
Summary: The study investigates the adiabatic evolution of electronic states induced by the lattice vibration of a chiral phonon, obtaining electronic orbital magnetization in the form of a topological second Chern form. The traditional theory needs refinement by introducing a k-resolved Born effective charge and accounting for the phonon-modified electronic energy and momentum-space Berry curvature contribution. The second Chern form may diverge when a Yang's monopole is near the parameter space of interest, as demonstrated in a gapped graphene model at the Brillouin zone corner.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Saquib Shamim, Wouter Beugeling, Pragya Shekhar, Kalle Bendias, Lukas Lunczer, Johannes Kleinlein, Hartmut Buhmann, Laurens W. Molenkamp
Summary: Researchers have successfully demonstrated the quantized spin Hall resistance in HgTe quantum wells alloyed with magnetic Mn atoms at very low temperatures, due to the Kondo screening effect. This work lays the foundation for future investigations into magnetically doped quantum spin Hall materials and the realization of chiral Majorana fermions.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Wei Chen
Summary: We propose a universal topological marker that can map the topological order to lattice sites for topological insulators and superconductors with Dirac models in any dimension and symmetry class. By introducing a topological operator derived from a momentum-space universal topological invariant, we construct the topological marker by alternating projectors, position operators, and Dirac matrices. The off-diagonal elements of the topological operator yield a non-local topological marker, representing a Wannier state correlation function, which decays with a diverging correlation length at topological phase transitions. Various prototype examples are employed to demonstrate the universality of our formalism.
Article
Materials Science, Multidisciplinary
Joanna Sitnicka, Kyungwha Park, Pawel Skupinski, Krzysztof Grasza, Anna Reszka, Kamil Sobczak, Jolanta Borysiuk, Zbigniew Adamus, Mateusz Tokarczyk, Andrei Avdonin, Irina Fedorchenko, Irina Abaloszewa, Sylwia Turczyniak-Surdacka, Natalia Olszowska, Jacek Kolodziej, Bogdan J. Kowalski, Haiming Deng, Marcin Konczykowski, Lia Krusin-Elbaum, Agnieszka Wolos
Summary: The MnBi2Te4/(Bi2Te3)(n) materials system shows promise for realizing the quantum anomalous Hall (QAH) state, but the presence of disorder has significant effects on its properties. The migration of Mn atoms between different layers induces coupling between the ferromagnetic layers and non-magnetic layers, affecting the system's behavior and surface band structure.
Article
Physics, Multidisciplinary
Chang Liu, YunYi Zang, Yan Gong, Ke He, XuCun Ma, QiKun Xue, YaYu Wang
Summary: In this study, we investigated the anomalous Hall effect in magnetically doped topological insulators with Mn and Cr doping. We found that the Mn-type effect is strengthened by reducing the film thickness, while the Cr-type effect shows the opposite trend. We provided a phenomenological physical picture to explain the evolution of magnetic order and anomalous Hall chirality in magnetically doped topological insulators.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Materials Science, Multidisciplinary
Takuya Okugawa, Tanay Nag, Dante M. Kennes
Summary: This study examines the transport properties of magnetically doped topological insulator thin films under correlated nonmagnetic disorder. The results show that different orientations of quasiperiodicity can lead to different topological phase transitions, including quantum anomalous Hall insulator, quantum spin Chern insulator, and quantum spin Hall insulator phases.
Article
Materials Science, Multidisciplinary
R. S. Akzyanov, A. L. Rakhmanov
Summary: In this study, the physics of the Josephson effect in odd-parity nematic superconductors is investigated. It is found that the interaction between nematicity and crystallographic axes in the superconductors leads to an unusual Josephson effect, which can be observed without any magnetization and exhibits an anomalous Josephson Hall effect.
Article
Physics, Multidisciplinary
Y. X. Zhao, Cong Chen, Xian-Lei Sheng, Shengyuan A. Yang
Summary: The study reveals the possibility of switching the two fundamental classes via Z(2) projective representations, allowing for unique topological phases to be achieved in different classes. For PT symmetry, the occurrence of this switching mechanism is demonstrated when P inverses the gauge transformation required to recover the original Z(2) gauge connections under P.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Qinghua Guo, Tianshu Jiang, Ruo-Yang Zhang, Lei Zhang, Zhao-Qing Zhang, Biao Yang, Shuang Zhang, C. T. Chan
Summary: Experimental observation of non-Abelian topological charges and edge states in a PT-symmetric transmission line network, along with the discovery of a non-Abelian quotient relation for the bulk-edge correspondence. This new topological property opens up possibilities for intriguing observable phenomena in the field of material science.
Article
Materials Science, Multidisciplinary
Xun-Jiang Luo, Xiao-Hong Pan, Xin Liu
Summary: The study demonstrates that the interplay between superconductors and magnetic fields based on the surface states of a weak topological insulator can lead to various helical or chiral Majorana hinge modes and even corner modes. The obtained higher-order topological superconductors can naturally behave as a TSC in DIII or D symmetry class due to their certain boundaries, surfaces, or hinges. These higher-order TSCs can be characterized by boundary topological invariants, such as surface Chern numbers or surface Z(2) topological invariants for surface TSCs.
Article
Physics, Multidisciplinary
Ari M. Turner, Erez Berg, Ady Stern
Summary: In this study, the stability of fragile topological bands protected by space-time inversion symmetry under strong electron-electron interactions is investigated. It is found that when these fragile bands are half filled, interactions can open a gap in the many-body spectrum without breaking any symmetry or mixing degrees of freedom from remote bands. The resulting ground state is not topologically ordered. The formation of fermionic bound states known as trions is crucial for this result, which may be relevant to recent experiments in magic angle twisted bilayer graphene at charge neutrality.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Chia-Hsiang Chen, Lukas Spree, Emmanouil Koutsouflakis, Denis S. Krylov, Fupin Liu, Ariane Brandenburg, Georgios Velkos, Sebastian Schimmel, Stanislav M. Avdoshenko, Alexander Fedorov, Eugen Weschke, Fadi Choueikani, Philippe Ohresser, Jan Dreiser, Bernd Buchner, Alexey A. Popov
Summary: This study demonstrates a facile solution-based procedure for preparing functional magnetic sub-monolayers by self-assembling fullerene-SMM derivatives on metal substrates, with DySc2N@C-80 grafted on gold showing magnetic bistability up to 10 K.
Article
Multidisciplinary Sciences
Shouvik Chatterjee, Shoaib Khalid, Hadass S. Inbar, Aranya Goswami, Taozhi Guo, Yu-Hao Chang, Elliot Young, Alexei Fedorov, Dan Read, Anderson Janotti, Chris J. Palmstrom
Summary: Controlling electronic properties through quantum confinement can modify carrier compensation and affect carrier mobility, leading to changes in magnetoresistance behavior; at the heteroepitaxial interface of a semimetal and a semiconductor, bonding mismatch results in the emergence of a two-dimensional, interfacial hole gas, accompanied by charge transfer across the interface, offering another way to adjust electronic structure and magnetotransport properties.
Article
Chemistry, Physical
A. Fedorov, G. Poelchen, S. Eremeev, S. Schulz, A. Generalov, C. Polley, C. Laubschat, K. Kliemt, N. Kaya, C. Krellner, E. Chulkov, K. Kummer, D. Yu Usachov, A. Ernst, D. V. Vyalikh
Summary: This study fills the knowledge gap on the electronic structure evolution of the divalent ferromagnetic semiconductor EuS, demonstrating its characteristics across the paramagnetic-ferromagnetic transition through experiments and first-principles calculations, highlighting the importance of Eu 4f-S 3p mixing for exchange-magnetic splittings and T-C value.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Lvchao Qiu, Ke Fang, Yubo Li, Shutao Huang, Guanxing Li, Songda Li, Hu He, Wentao Yuan, Hangsheng Yang, Wei Tian, Yong Wang
Summary: A novel strategy was developed to prepare array of single crystalline anatase TiO2 nanotubes (SC-ATONAs), which showed significant enhancement in photocatalytic activity and UV photo response performance compared to polycrystalline counterparts. Growth of SC-ATONAs was achieved by establishing a crystallization temperature gradient along the tube wall, paving the way to prepare single-crystalline nanotubes with superior performance for other materials.
PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL
(2021)
Article
Physics, Multidisciplinary
Rui Lou, Alexander Fedorov, Qiangwei Yin, Andrii Kuibarov, Zhijun Tu, Chunsheng Gong, Eike F. Schwier, Bernd Buechner, Hechang Lei, Sergey Borisenko
Summary: The entanglement of charge density wave (CDW), superconductivity, and topologically nontrivial electronic structure has been discovered in the kagome metal AV3Sb5 (A = K, Rb, Cs) family recently. Using high-resolution angle-resolved photoemission spectroscopy, the electronic properties of CDW and superconductivity in CsV3Sb5 are studied. The spectra around K over line exhibit a peak-dip-hump structure associated with two separate branches of dispersion, indicating the isotropic CDW gap opening below EF. The presence of a superconducting gap on both the electron band around Gamma over line and the flat band around K suggests multiband superconductivity. Our results shed light on the controversial origin of the CDW and provide insights into the relationship between CDW and superconductivity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Max Mende, Khadiza Ali, Georg Poelchen, Susanne Schulz, Vladislav Mandic, Artem V. Tarasov, Craig Polley, Alexander Generalov, Alexander V. Fedorov, Monika Guttler, Clemens Laubschat, Kristin Kliemt, Yury M. Koroteev, Evgueni V. Chulkov, Kurt Kummer, Cornelius Krellner, Dmitry Yu. Usachov, Denis V. Vyalikh
Summary: The study reveals the existence of novel temperature scales and distinct electronic structures at the surfaces of strongly correlated f materials, indicating the potential for engineering novel nanostructural objects with diverse functionalities. Ab initio calculations can reliably predict the unusual electronic and spin structures of these surfaces, offering new insights for materials science research and development of advanced materials.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Artem K. Grebenko, Dmitry Krasnikov, Anton Bubis, Vasily S. Stolyarov, Denis V. Vyalikh, Anna A. Makarova, Alexander Fedorov, Aisuluu Aitkulova, Alena A. Alekseeva, Evgeniia Gilshtein, Zakhar Bedran, Alexander N. Shmakov, Liudmila Alyabyeva, Rais N. Mozhchil, Andrey M. Ionov, Boris P. Gorshunov, Kari Laasonen, Vitaly Podzorov, Albert G. Nasibulin
Summary: This article introduces a new method for the large-scale production of high-purity graphene using the Boudouard reaction and CO-driven catalyst engineering. This approach not only suppresses the growth of the second layer of graphene, but also provides a simple and reliable technique for surface cleaning.
Article
Chemistry, Multidisciplinary
Vladimir Voroshnin, Artem V. Tarasov, Kirill A. Bokai, Alla Chikina, Boris V. Senkovskiy, Niels Ehlen, Dmitry Yu. Usachov, Alexander Gruneis, Maxim Krivenkov, Jaime Sanchez-Barriga, Alexander Fedorov
Summary: A magnetic field can modify optical properties and induce valley splitting in a monolayer of molybdenum disulfide (MoS2). In this study, a scalable method to synthesize MoS2 monolayers on a magnetic graphene/Co system was demonstrated. The magnetic proximity effect was observed using spin- and angle-resolved photoemission spectroscopy, showing spin-splitting and spin-canting effects in the valence band. Density functional theory calculations revealed the localization of spin components on Co atoms and MoS2 layers, and predicted the effects of out-of-plane magnetization on spin-splitting and valley asymmetry. These findings suggest the potential for control of optical transitions in MoS2 through Co magnetization.
Article
Chemistry, Multidisciplinary
Zhaohui Ren, Luoyuan Ruan, Lichang Yin, Karthik Akkiraju, Livia Giordano, Zhongran Liu, Shi Li, Zixing Ye, Songda Li, Hangsheng Yang, Yong Wang, He Tian, Gang Liu, Yang Shao-Horn, Gaorong Han
Summary: It is reported that surface oxygen vacancies can be confined electrostatically near the perimeter interface between Pt {111} nanocrystals and the negative polar surface (001) of ferroelectric PbTiO3. This catalyst demonstrates tunable catalytic CO oxidation kinetics by increasing the O-2 gas pressure, opening a new pathway for CO oxidation catalytic activity.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Benjamin Schrunk, Yevhen Kushnirenko, Brinda Kuthanazhi, Junyeong Ahn, Lin-Lin Wang, Evan O'Leary, Kyungchan Lee, Andrew Eaton, Alexander Fedorov, Rui Lou, Vladimir Voroshnin, Oliver J. Clark, Jamie Sanchez-Barriga, Sergey L. Bud'ko, Robert-Jan Slager, Paul C. Canfield, Adam Kaminski
Summary: The Fermi surface plays a crucial role in material properties. Fermi arcs can be signatures of unusual electronic states and can be obtained by breaking specific symmetries. In this study, experimental evidence is presented showing the emergence of hole- and electron-like Fermi arcs below the Neel temperature in an antiferromagnetic state. This magnetic splitting effect is unique as it creates bands with opposing curvature that change with temperature.
Article
Multidisciplinary Sciences
Sergey Borisenko, Alexander Fedorov, Andrii Kuibarov, Marco Bianchi, Volodymyr Bezguba, Paulina Majchrzak, Philip Hofmann, Peter Baumgaertel, Vladimir Voroshnin, Yevhen Kushnirenko, Jaime Sanchez-Barriga, Andrei Varykhalov, Ruslan Ovsyannikov, Igor Morozov, Saicharan Aswartham, Oleh Feia, Luminita Harnagea, Sabine Wurmehl, Alexander Kordyuk, Alexander Yaresko, Helmuth Berger, Bernd Buechner
Summary: Fermi surfaces are crucial for understanding the properties of crystalline metals and semiconductors. A new angle-resolved photoemission spectroscopy technique is presented that allows for fast and high-resolution mapping of the Fermi surface.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Y. Falke, N. Ehlen, G. Marini, A. Fedorov, V. Y. Voroshnin, B. Senkovskiy, K. Nikonov, M. Hoesch, T. K. Kim, L. Petaccia, G. Di Santo, T. Szkopek, G. Profeta, A. Grueneis
Summary: This study investigates electron-phonon coupling in the CDW phase of VSe2 using Raman spectroscopy, ARPES, and ab initio calculations, revealing the appearance of a new Raman peak induced by CDW-induced zone folding and the suppression of ARPES intensity. The new Raman peak is in line with the observation of a kink feature in the ARPES spectral function. An analysis yields an EPC constant of lambda = 0.3, showing agreement with the calculations and highlighting the CDW phase as a promoter of EPC pathways to optical phonons affecting the Raman spectrum.
Review
Materials Science, Multidisciplinary
Guanxing Li, Ke Fang, Yang Ou, Wentao Yuan, Hangsheng Yang, Ze Zhang, Yong Wang
Summary: The anatase TiO2 (001) surface, known for its excellent performance, undergoes reconstruction to a (1 x 4)-(001) surface due to its high reactivity, potentially altering its properties. Recent advances in surface science have elucidated the intrinsic physical and chemical properties of this surface. Studying the structure, formation mechanism, stability, and surface chemistry of the reconstructed TiO2 (001) surface is crucial for understanding its behavior.
PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Liping Sheng, Songda Li, Zhaoxia Ma, Fei Wang, Hu He, Yi Gao, Beien Zhu, Yong Wang, Hangsheng Yang
Summary: The interaction of O-2 with NO reduction pathway greatly affects the NO removal efficiency and N2O formation during the NH3-SCR process over the Pd/CeO2 catalyst. Below 175 degrees C, fast-SCR is the main reaction route for NO removal, while in the temperature range of 175-250 degrees C, NH3 facilitates the reduction of NO but also induces the formation of N2O. Above 250 degrees C, NH3 is severely oxidized leading to excess N2O formation even in the presence of a low amount of O-2.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
