Article
Physics, Multidisciplinary
Jia Yu, Tong Liu, BinBin Ruan, Kang Zhao, QingSong Yang, MengHu Zhou, ZhiAn Ren
Summary: The study investigates the evolution of superconductivity and magnetism in EuFeAs2 and Eu0.9Pr0.1FeAs2 through cobalt doping. Cobalt doping has little effect on the Eu-related antiferromagnetic transition in EuFeAs2, but rapidly decreases the Fe-related spin density wave transition temperature, while inducing superconductivity. In Eu0.9Pr0.1FeAs2, magnetism and superconductivity show similar evolutions upon cobalt doping, with the highest transition temperature reaching 30.6 K.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2021)
Article
Physics, Multidisciplinary
Alessandro Ricci, Nicola Poccia, Gaetano Campi, Shrawan Mishra, Leonard Mueller, Boby Joseph, Bo Shi, Alexey Zozulya, Marcel Buchholz, Christoph Trabant, James C. T. Lee, Jens Viefhaus, Jeroen B. Goedkoop, Agustinus Agung Nugroho, Markus Braden, Sujoy Roy, Michael Sprung, Christian Schuessler-Langeheine
Summary: Using x-ray photon correlation spectroscopy, fluctuations in stripe-type spin order of a layered nickelate were observed on timescales of tens of minutes across a wide temperature range. These fluctuations exhibit anomalous temperature dependence, slowing down at intermediate temperatures and speeding up during heating and cooling, reflecting a direct connection with spatial correlations. The decay of nickelate stripe correlations at low temperatures, similar to the competition between stripes and superconductivity in cuprates, occurs through loss of both spatial and temporal correlations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Darshana Wickramaratne, Menashe Haim, Maxim Khodas, I. I. Mazin
Summary: Hybrid Ising superconductor-ferromagnetic insulator heterostructures offer a unique opportunity to explore the interplay between proximity-induced magnetism, spin-orbit coupling, and superconductivity, leading to a comprehensive explanation of complex effects such as an increase in superconducting gap magnitude, broadening of tunneling peaks, hysteretic behavior in tunneling conductance, and nematic symmetry breaking in the superconducting state. These effects are primarily attributed to the interplay between proximity-induced exchange splitting and intrinsic defects.
Article
Materials Science, Multidisciplinary
R. Idczak, M. Babij, P. Sobota, W. Nowak, R. Konieczny, Z. Bukowski, V. H. Tran
Summary: The interplay of magnetism and superconductivity in Eu(Fe1-xCox)As-2 compounds at low temperatures was systematically studied using polycrystalline samples. The results show that all three compounds exhibit long-range antiferromagnetic order and superconductivity in FeAs layers.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Applied
Karciano J. S. Silva, David A. Landinez-Tellez, Petrucio Barrozo, I. Garcia-Fornaris, J. Albino Aguiar
Summary: This study reports on the sintering, structural, morphological, electrical, and magnetic characterization of the superconducting FeSe0.88. The sample was prepared using the solid-state reaction method at 600 degrees C in an evacuated borosilicate tube. X-ray diffractograms revealed the formation of two minor impurity phases, Fe7Se8 and FeSe, both with hexagonal structures, which are not superconducting. Resistivity measurements showed the onset superconducting temperature at Tconset is approximately 8.6 K. Magnetic measurements demonstrated a ferromagnetic-paramagnetic phase transition around 875 K for the FeSe0.88 compound.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2023)
Article
Physics, Multidisciplinary
Erik S. Sorensen, Andrei Catuneanu, Jacob S. Gordon, Hae-Young Kee
Summary: This study focuses on the Kitaev-Gamma ladder model to explore the phase space of disordered states potentially becoming spin liquids in the two-dimensional limit. The research reveals a rich phase diagram with 15 distinct phases emerging due to the competition between interactions and magnetic field, including a highly entangled phase with staggered chirality. By comparing results with a C-3 symmetric cluster of the two-dimensional honeycomb lattice, insights into possible spin liquids in the two-dimensional limit are provided.
Article
Chemistry, Multidisciplinary
Yongbing Shen, Hiroshi Ito, Haitao Zhang, Hideki Yamochi, Goulven Cosquer, Carmen Herrmann, Toshiaki Ina, Shinji K. Yoshina, Brian K. Breedlove, Akihiro Otsuka, Manabu Ishikawa, Takefumi Yoshida, Masahiro Yamashita
Summary: The research team introduced an organic-inorganic molecular hybrid compound that exhibits both metallic conduction and SMM behavior in the temperature range of 12-26 K for the first time.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Jun Cui, Emil Vinas Bostroem, Mykhaylo Ozerov, Fangliang Wu, Qianni Jiang, Jiun-Haw Chu, Changcun Li, Fucai Liu, Xiaodong Xu, Angel Rubio, Qi Zhang
Summary: The research team observed magnon-induced chiral phonons and chirality selective magnon-phonon hybridization in the antiferromagnet FePSe3, which provides new insights for the development of angular momentum-based hybrid phononic and magnonic devices.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Guanghui Cheng, Mohammad Mushfiqur Rahman, Zhiping He, Andres Llacsahuanga Allcca, Avinash Rustagi, Kirstine Aggerbeck Stampe, Yanglin Zhu, Shaohua Yan, Shangjie Tian, Zhiqiang Mao, Hechang Lei, Kenji Watanabe, Takashi Taniguchi, Pramey Upadhyaya, Yong P. Chen
Summary: The researchers studied the heterostructures of CrI3 and CrCl3 using magneto-optical Kerr effect microscopy and found ferromagnetic interfacial coupling between the two materials. They also discovered that the coercivity of the heterostructure can be controlled by an electric field.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
C. Vaswani, J. H. Kang, M. Mootz, L. Luo, X. Yang, C. Sundahl, D. Cheng, C. Huang, R. H. J. Kim, Z. Liu, Y. G. Collantes, E. E. Hellstrom, I. E. Perakis, C. B. Eom, J. Wang
Summary: The study identifies a hybrid Higgs mode in iron-based high-temperature superconductors and demonstrates its quantum control by light. The tunable coherent oscillation of the complex order parameter in these superconductors suggests the appearance and control of the Higgs mode through light tuning of interband interaction.
NATURE COMMUNICATIONS
(2021)
Review
Environmental Sciences
Qingqing Tao, Jingtao Bi, Xin Huang, Rongli Wei, Ting Wang, Yanan Zhou, Hongxun Hao
Summary: This review discusses the potentials of Fe2O3 in water remediation, including synthesis methods, applications and related mechanisms, as well as strategies for optimizing the remediation processes. Recommendations for the development of novel Fe2O3-related materials and its practical applications are also proposed.
Article
Materials Science, Multidisciplinary
Areg Ghazaryan, Ammar Kirmani, Rafael M. Fernandes, Pouyan Ghaemi
Summary: We demonstrate the formation of robust zero-energy modes near magnetic impurities in the iron-based superconductor FeSe1-xTex. The Zeeman field generated by the impurity favors spin-triplet interorbital pairing over the spin-singlet intraorbital pairing found in the bulk. The preferred spin-triplet pairing preserves time-reversal symmetry and exhibits topological properties, with robust, topologically protected zero modes emerging at the boundaries between different pairing states.
Article
Physics, Multidisciplinary
Rui-Xing Zhang, S. Das Sarma
Summary: The quasi-two-dimensional thin films of iron-based superconductors have been established as a new high-temperature platform for hosting intrinsic time-reversal-invariant helical topological superconductivity. Experimental results have shown that an applied electric field can serve as a topological switch for helical Majorana edge modes in FeSC thin films.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Condensed Matter
J. M. Wilde, A. Sapkota, Q-P Ding, M. Xu, W. Tian, S. L. Bud'ko, Y. Furukawa, A. Kreyssig, P. C. Canfield
Summary: The magnetic order of Mn-doped CaK(Fe1-xMnx)(4)As-4 compounds is consistent with the hedgehog spin vortex crystal (hSVC) order found in Ni-doped CaKFe4As4. The hSVC state is characterized by stripe-type propagation vectors and simple antiferromagnetic stacking. The hSVC state in Mn-doped 1144 compound coexists with superconductivity and shows a quantum phase transition associated with the suppression of the AFM transition temperature.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Georgios Angelis, Golfo G. Kordopati, Eleni Zingkou, Anastasia Karioti, Georgia Sotiropoulou, Georgios Pampalakis
Summary: Research suggests that Enceladus, one of Saturn's satellites, may have a soda-type subsurface ocean with conditions potentially able to support life, as well as an iron ore-based core. The ocean chemistry related to Enceladus could support the development of Fe-based hydrothermal vents, which are thought to be potential cradles of life. Chemical structures formed in this environment can catalyze the transformation of simple organic prebiotic molecules into complex polymers, indicating that basic biochemical precursors may have emerged in Enceladus.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Editorial Material
Multidisciplinary Sciences
Morten H. Christensen, Turan Birol
Article
Physics, Multidisciplinary
Andreas Kreisel, Brian M. Andersen, Astrid T. Romer, Ilya M. Eremin, Frank Lechermann
Summary: The study investigated the superconducting properties of infinite-layer nickelates, revealing a superconducting instability transition driven by strong fluctuations in the dz2 orbital states. The properties of the superconducting condensates were discussed based on experiments probing the detailed superconducting gap structure.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Ryan Stadel, Dmitry D. Khalyavin, Pascal Manuel, Koji Yokoyama, Saul Lapidus, Morten H. Christensen, Rafael M. Fernandes, Daniel Phelan, Duck Young Chung, Raymond Osborn, Stephan Rosenkranz, Omar Chmaissem
Summary: The study of iron-pnictide superconductors is important for understanding unconventional high-temperature superconductivity. By using neutron diffraction, researchers have observed three competing magnetic orders in LaFeAs1-xPxO and found that the reduction in electronic correlations leads to larger Fermi surfaces and sequential stabilization of multiple magnetic anisotropies.
COMMUNICATIONS PHYSICS
(2022)
Article
Multidisciplinary Sciences
Z. Guguchia, C. Mielke, D. Das, R. Gupta, J. -X. Yin, H. Liu, Q. Yin, M. H. Christensen, Z. Tu, C. Gong, N. Shumiya, Md Shafayat Hossain, Ts Gamsakhurdashvili, M. Elender, Pengcheng Dai, A. Amato, Y. Shi, H. C. Lei, R. M. Fernandes, M. Z. Hasan, H. Luetkens, R. Khasanov
Summary: In this study, pressure-tuned and ultra-low temperature muon spin spectroscopy was used to uncover the unconventional nature of superconductivity in RbV3Sb5 and KV3Sb5. It was found that at ambient pressure, time-reversal symmetry breaking charge order was observed in RbV3Sb5, and the superconducting state displayed a nodal energy gap and reduced superfluid density. Applying pressure suppressed the charge-order transitions, increased the superfluid density, and progressively evolved the superconducting state from nodal to nodeless. The optimal superconductivity state was found to break time-reversal symmetry. These results offer unique insights into the nature of the pairing state and highlight the tunable nodal kagome superconductivity competing with time-reversal symmetry-breaking charge order.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Weijiong Chen, Clara Neerup Breio, Freek Massee, Milan P. Allan, Cedomir Petrovic, J. C. Seamus Davis, Peter J. Hirschfeld, Brian M. Andersen, Andreas Kreisel
Summary: The authors used scanning tunneling microscopy to detect the orbital order in the superconductor CeCoIn5, which is enhanced in the superconducting state as predicted. Visualization of atomic-orbital degrees of freedom is a challenge in scanned microscopy. Sublattice-resolved superconductive QPI techniques represent a new approach for studying hidden orbital order.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Qianni Jiang, Yue Shi, Morten H. Christensen, Joshua J. Sanchez, Bevin Huang, Zhong Lin, Zhaoyu Liu, Paul Malinowski, Xiaodong Xu, Rafael M. Fernandes, Jiun-Haw Chu
Summary: In this study, the authors investigate the nematic susceptibility and its relationship with spin fluctuations in Fe1+yTe1-xSex using elastoresistivity measurement. They find that the nematic fluctuations in two symmetry channels are closely linked to the corresponding spin fluctuations, and observe an unusual temperature dependence of the nematic susceptibility attributed to the loss of coherence of the d(xy) orbital. The research highlights the importance of orbital differentiation on the nematic properties of iron-based materials.
COMMUNICATIONS PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Shinibali Bhattacharyya, Andreas Kreisel, X. Kong, T. Berlijn, Astrid T. Romer, Brian M. Andersen, P. J. Hirschfeld
Summary: The nature of the superconducting order parameter in Sr2RuO4 has attracted significant attention. Scanning tunneling spectroscopy has been suggested as the best method to directly resolve the small superconducting gap. A recent experiment using Bogoliubov quasiparticle interference imaging (BQPI) indicates that the dx2-y2 gap symmetry is appropriate for Sr2RuO4. In this study, a material-specific theoretical approach is used to calculate the density of states detected in scanning tunneling microscopy experiments, and the results suggest a s' + idxy gap order parameter as the most probable state.
Article
Materials Science, Multidisciplinary
Clara N. Breio, Brian M. Andersen
Summary: It is a challenge to describe the proliferation of correlated topological electronic phases and their filling dependence at a certain magic relative twist angle of two graphene sheets. In this study, we use a self-consistent real-space Hartree-Fock method to investigate the preferred ordered phases as a function of Coulomb interaction strength and moire flat-band filling factor. We find that a quantum valley Hall phase is present at all integer fillings for sufficiently large interactions. Furthermore, spontaneous spin/valley polarization is present in the ground state at nonzero integer fillings, leading to Chern insulator phases and anomalous quantum Hall effects.
Article
Physics, Multidisciplinary
Yun-Peng Huang, Panagiotis Kotetes
Summary: We propose an alternative method to stabilize magnetic skyrmion textures by relying solely on the emergence of flux in the system's ground state, without the need for Dzyaloshinkii-Moriya interactions, magnetic anisotropy, or an external Zeeman field. We discuss the scenarios that lead to a nonzero flux and identify the accessible magnetic skyrmion ground states in its presence. Furthermore, we explore the chiral superconductors obtained for the surface states of a topological crystalline insulator when two types of magnetic skyrmion crystals coexist with a pairing gap. Our work opens up possibilities for minimal engineering of topological superconductivity and promises to discover functional topological materials and devices that may be more compatible with electrostatic control than the currently explored skyrmion-Majorana platforms.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Ethan T. Ritz, Henrik S. Roising, Morten H. Christensen, Turan Birol, Brian M. Andersen, Rafael M. Fernandes
Summary: Recent experiments have shown that changes in the c-axis lattice parameter strongly affect the phase diagrams of the kagome superconductors AV3Sb5. It has been found that c-axis deformations primarily impact the overlap between the pz orbitals of the Sb apical bonds, thus significantly influencing low-energy electronic states with Sb character. Based on the orbital-selective character of c-axis strain, it is argued that these electronic states experience a non-negligible attractive electron-phonon pairing interaction mediated by fluctuations in the apical Sb bonds. Therefore, a multiband model is proposed to explain the superconductivity in AV3Sb5, which includes both the Sb pocket and the V-derived van Hove singularities.
Article
Materials Science, Multidisciplinary
Merce Roig, Astrid T. Romer, P. J. Hirschfeld, Brian M. Andersen
Summary: The superconducting instabilities of the 2D extended repulsive one-band Hubbard model depend on electron density, band, and interaction parameters. The results show that different pairing symmetries dominate in the absence or presence of repulsive longer-range Coulomb interactions.
Article
Materials Science, Multidisciplinary
Morten H. Christensen, Turan Birol, Brian M. Andersen, Rafael M. Fernandes
Summary: This study investigates the complex charge-ordered states in AV3Sb5, a recently discovered vanadium-based kagome metal. The results show the existence of mixed imaginary charge density wave (iCDW) and real charge density wave (rCDW) configurations, as well as different types of iCDW orders. These charge-ordered states exhibit various types of uniform magnetic orders and unique magnetostriction, magnetoelectric, and magnetoelectrostriction properties. Experimental probing can identify the specific iCDW state present in these compounds.
Article
Materials Science, Multidisciplinary
Fei Chen, Rafael M. Fernandes, Morten H. Christensen
Summary: By calculating the dynamic spin susceptibility of 3D superconductors, we find that the appearance of a spin resonance mode is determined by the topology of hot lines connected by the magnetic wave vector on the Fermi surface, which has implications for the study of unconventional superconductors.
Article
Physics, Multidisciplinary
Daniel Steffensen, Morten H. Christensen, Brian M. Andersen, Panagiotis Kotetes
Summary: We present a detailed investigation of the topological phases and Majorana fermion (MF) excitations that arise from the bulk interplay between (un)conventional one- and two-band spin-singlet superconductivity and a number of magnetic texture crystals. Our analysis reveals a multitude of accessible topological phases with distinct edge modes, originating from the interplay between topological phases with gapped and nodal bulk energy spectra.
PHYSICAL REVIEW RESEARCH
(2022)