Article
Chemistry, Multidisciplinary
Min Zhang, Guihua Tang, Yifei Li
Summary: This study investigates the lattice thermal conductivities of PbTe and PbSe as a function of hydrostatic pressure using first-principles calculations, revealing the important potential for thermal conductivity reduction in the Pnma phase.
Article
Multidisciplinary Sciences
Yuan Cao, Daniel Rodan-Legrain, Jeong Min Park, Noah F. Q. Yuan, Kenji Watanabe, Takashi Taniguchi, Rafael M. Fernandes, Liang Fu, Pablo Jarillo-Herrero
Summary: In magic-angle twisted bilayer graphene, intertwined phases with broken rotational symmetry have been identified, showing strong thermodynamic anisotropy and appearing above the underdoped region of the superconducting dome. A reduction in critical temperature is observed when it intersects with the superconducting dome, with the superconducting state exhibiting anisotropic response to in-plane magnetic fields, suggesting nematic ordering plays a significant role in the low-temperature phases of magic-angle TBG.
Article
Chemistry, Multidisciplinary
Liyun Zhao, Yingjie Jiang, Chun Li, Yin Liang, Zhongming Wei, Xiaoding Wei, Qing Zhang
Summary: By applying hydrostatic pressure, anisotropic deformation and efficient manipulation of near-infrared light emission in thin-layered Indium selenide (InSe) were observed, which strongly correlated to the layer numbers. The compression of the InSe lattice and the widening of the band gap result in an emission blue shift for layer numbers greater than 20, while an efficient emission red shift is observed for layer numbers less than or equal to 15, due to predominant uniaxial interlayer compression. These findings enhance our understanding of pressure-induced lattice deformation and optical transition evolution in InSe and have potential applications to other 2D materials.
Review
Physics, Applied
Peng Liu, Bin Lei, Xianhui Chen, Lan Wang, Xiaolin Wang
Summary: This review summarizes recent advances in electric-field-gated superconductivity in various ultrathin superconducting materials, including iron-based superconductors, transition-metal dichalcogenides, honeycomb bilayer superconductors, and cuprates. It highlights the power of electric-double-layer transistors and ionic field-effect transistors as electric-field gating strategies, and offers a perspective on open challenges and future development paths in this field.
NATURE REVIEWS PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Wen Wan, Rishav Harsh, Paul Dreher, Fernando de Juan, Miguel M. Ugeda
Summary: Chemical substitution is a promising approach to explore collective phenomena in low-dimensional quantum materials. Transition metal dichalcogenide alloys are shown to be ideal platforms for this purpose. We demonstrate the emergence of superconductivity in single-layer TaSe2 through minute electron doping using substitutional W atoms. The temperature and magnetic field dependence of the superconducting state of Ta1-delta W delta Se2 are investigated using scanning tunneling spectroscopy. A superconducting dome spanning 0.003 < delta < 0.03 with a maximized critical temperature of 0.9 K is observed, which is significantly higher than that of bulk TaSe2 (T-C = 0.14 K). The superconductivity is attributed to an increase in density of states as the Fermi surface approaches a van Hove singularity, but gradually weakens as the singularity is reached, shaping the superconducting dome. Doping-dependent measurements suggest the development of a Coulomb glass phase triggered by disorder due to W dopants.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Aleksandra Deptuch, Ryszard Duraj, Andrzej Szytula, Boguslaw Penc, Ewa Juszynska-Galazka, Stanislaw Baran
Summary: The structural and magnetic properties of CoMn0.88Cu0.12Ge were investigated using X-ray diffraction and differential scanning calorimetry (DSC). The applied hydrostatic pressure up to 12 kbar affects the magnetic properties of the compound.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Multidisciplinary
Xing Xie, Junnan Ding, Biao Wu, Haihong Zheng, Shaofei Li, Chang-Tian Wang, Jun He, Zongwen Liu, Jian-Tao Wang, Yanping Liu
Summary: This study presents a dynamic tuning method for twisted WSe2/WSe2 homobilayers and demonstrates the powerful tuning of interlayer coupling. It is found that the introduction of a moire superlattice leads to hybridized excitons and different pressure-evolution exciton behaviors compared to natural bilayers.
Article
Materials Science, Multidisciplinary
He Zhou, Dekun Wang, Zhe Li, Junzhuang Cong, Ziyuan Yu, Shuo Zhao, Peng Jiang, Daoyong Cong, Xinqi Zheng, Kaiming Qiao, Hu Zhang
Summary: This study investigates the effect of hydrostatic pressure on the magnetostructural transformation and magnetocaloric effect in Mn0.94Fe0.06NiGe compound. The results show that hydrostatic pressure can effectively regulate the magnetostructural transition and enhance the magnetocaloric effect. First-principles calculations reveal the underlying mechanism of the regulation effect under hydrostatic pressure.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Gustavo A. Lombardi, Kamal Mydeen, Roman Gumeniuk, Andreas Leithe-Jasper, Walter Schnelle, Ricardo D. dos Reis, Michael Nicklas
Summary: In this study, we conducted electrical resistivity and X-ray diffraction (XRD) investigations on the filled skutterudite superconductors LaPt4Ge12 and PrPt4Ge12 under hydrostatic pressure. The results revealed a linear suppression of the superconducting transition temperature Tc with increasing pressure, although the effect of pressure on Tc was relatively weak. From the analysis of XRD data, we obtained bulk moduli of B = 106 GPa and B = 83 GPa for LaPt4Ge12 and PrPt4Ge12, respectively. It was found that hydrostatic pressure mainly affected the superconducting properties of LaPt4Ge12 and PrPt4Ge12 through changes in volume, while substitution of Pr for La1-xPrxPt4Ge12 showed more complex characteristics.
Article
Materials Science, Multidisciplinary
Gao-Wei Qiu, Yi Zhou
Summary: Under the influence of a magnetic field, two weakly linked superconducting ultrathin films exhibit different superconducting states, with one characterized by staggered supercurrent loops and a superfluid density wave, and the other by uniform superfluid density. The phase transition between these two states falls within a specific universality class.
Article
Materials Science, Multidisciplinary
Aleksei S. Komlev, Rodion A. Makarin, Konstantin P. Skokov, Alisa M. Chirkova, Radel R. Gimaev, Vladimir I. Zverev, Nikolai V. Baranov, Nikolai S. Perov
Summary: This paper presents the results of measuring the structural, magnetic, and caloric properties of the (Fe,Ru)Rh alloy, which has demonstrated a new record of reversible magnetocaloric effect. The analysis of these results allows for understanding the mechanisms that affect the magnetocaloric effect value at low doping.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Katerina P. Hilleke, Eva Zurek
Summary: The study explains the structure and stability of metal hydride phases using Density Functional Theory-Chemical Pressure (DFT-CP) method, revealing the reasons why certain elements adopt specific structure types and how internal pressure leads to the opening of H-24 polyhedra. The stability of phases is enhanced by filling the shared hydrogen network with additional atoms.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yunyi Zang, Felix Kuester, Jibo Zhang, Defa Liu, Banabir Pal, Hakan Deniz, Paolo Sessi, Matthew J. Gilbert, Stuart S. P. Parkin
Summary: By introducing superconductivity, spin-orbital coupling, and topological states, we engineered an artificial topological superconductor and detected features directly linked to topological surface states.
Article
Physics, Multidisciplinary
Wen-Ti Guo, Lu Huang, Yanmin Yang, Zhigao Huang, Jian-Min Zhang
Summary: This study demonstrates that pressure strain can induce a topological quantum phase transition in the magnetic topological insulator MnBi2Te4 by modulating its electronic band structure. The findings suggest that strain engineering could be a feasible approach for manipulating the electronic properties of intrinsic magnetic insulators.
NEW JOURNAL OF PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
J. Hou, K. Y. Chen, J. P. Sun, Z. Zhao, Y. H. Zhang, P. F. Shan, N. N. Wang, H. Zhang, K. Zhu, Y. Uwatoko, H. Chen, H. T. Yang, X. L. Dong, H. -J. Gao, J. -G. Cheng
Summary: Recent studies on CsV3Sb5 show that there is a complex interaction between unconventional charge density waves and superconductivity. Substituting Ti for V in CsV3-xTixSb5 can disturb the charge density waves and produce different superconducting phases. High pressure studies on Ti-doped CsV3-xTixSb5 samples reveal the competition and coexistence of charge density waves and superconductivity. These results provide more insight into the competing electronic orders in Ti-doped kagome superconductors.
Article
Instruments & Instrumentation
G. Simutis, A. Bollhalder, M. Zolliker, J. Kuespert, Q. Wang, D. Das, F. Van Leeuwen, O. Ivashko, O. Gutowski, J. Philippe, T. Kracht, P. Glaevecke, T. Adachi, M. Zimmermann, S. Van Petegem, H. Luetkens, Z. Guguchia, J. Chang, Y. Sassa, M. Bartkowiak, M. Janoschek
Summary: We propose an in situ uniaxial pressure device designed for small angle x-ray and neutron scattering experiments at low temperatures and high magnetic fields. The device uses a rod with an integrated transducer to transmit force to the sample, allowing forces of up to 200 N in both compressive and tensile configurations. It can be operated in a continuous-pressure mode with feedback control while the temperature is changing. The device is compatible with various instruments and cryostats through simple and exchangeable adapters, and it supports rapid sample changes with multiple sample holders.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
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
Chemistry, Physical
Charlotte Pughe, Otto H. J. Mustonen, Alexandra S. Gibbs, Stephen Lee, Rhea Stewart, Ben Gade, Chennan Wang, Hubertus Luetkens, Anna Foster, Fiona C. Coomer, Hidenori Takagi, Edmund J. Cussen
Summary: Ba2CuTeO6 is a material with a two-leg spin ladder structure of Cu2+ cations, which can be chemically tuned by substituting non-magnetic Zn2+ at the Cu2+ site. The substitution partitions the spin ladders into clusters, leading to a transition from long-range order to spin-freezing as the Zn2+ substitution increases. This provides a well-controlled tuning of the magnetic disorder and a model system for studying defects and segmentation in low-dimensional quantum magnets.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Benjamin Kintzel, Michael Boehme, Daniel Plaul, Helmar Goerls, Nicolas Yeche, Felix Seewald, Hans -Henning Klauss, Andrei A. Zvyagin, Erik Kampert, Thomas Herrmannsdoerfer, Gwendolyne Pascua, Christopher Baines, Hubertus Luetkens, Winfried Plass
Summary: The trinuclear high-spin iron(III) complex [Fe3Cl3(saltag(Br))(py)(6)]ClO4 was synthesized and characterized. Magnetic measurements showed antiferromagnetic exchange between the iron(III) ions, resulting in a geometrically spin-frustrated ground state. High-field magnetization and muon-spin relaxation experiments confirmed the isotropic nature of the magnetic exchange and the absence of significant intermolecular interactions. The complex is considered an ideal candidate for studying spin-electric effects.
INORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Yigui Zhong, Jinjin Liu, Xianxin Wu, Zurab Guguchia, J. -x. Yin, Akifumi Mine, Yongkai Li, Sahand Najafzadeh, Debarchan Das, Charles Mielke, Rustem Khasanov, Hubertus Luetkens, Takeshi Suzuki, Kecheng Liu, Xinloong Han, Takeshi Kondo, Jiangping Hu, Shik Shin, Zhiwei Wang, Xun Shi, Yugui Yao, Kozo Okazaki
Summary: The newly discovered kagome superconductors offer a promising platform to explore the interplay between band topology, electronic order, and lattice geometry. However, the nature of the superconducting ground state and the electron pairing symmetry in this system is still not well understood. In this study, we directly observed a nodeless and nearly isotropic superconducting gap in the momentum space of two different kagome superconductors using high-resolution and low-temperature angle-resolved photoemission spectroscopy. The unique properties of the superconducting gap are independent of charge order in the normal state. This comprehensive characterization provides essential information about the electron pairing symmetry in kagome superconductors and advances our understanding of superconductivity and intertwined electronic orders in quantum materials.
Article
Instruments & Instrumentation
Lars Gerchow, Sayani Biswas, Gianluca Janka, Carlos Vigo, Andreas Knecht, Stergiani Marina Vogiatzi, Narongrit Ritjoho, Thomas Prokscha, Hubertus Luetkens, Alex Amato
Summary: The pioneering work on Muon-induced x-ray emission (MIXE) technique was conducted at the Paul Scherrer Institute (PSI) in the 1980s for non-destructive assessment of elemental compositions. In recent years, this method has been improved and adopted at many muon facilities worldwide. The GermanIum Array for Non-destructive Testing (GIANT) setup at PSI is a dedicated MIXE spectrometer that offers excellent performance and has been used for various applications such as archaeological research and collaboration with the industry.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Humanities, Multidisciplinary
Sayani Biswas, Isabel Megatli-Niebel, Lilian Raselli, Ronald Simke, Thomas Elias Cocolios, Nilesh Deokar, Matthias Elender, Lars Gerchow, Herbert Hess, Rustem Khasanov, Andreas Knecht, Hubertus Luetkens, Kazuhiko Ninomiya, Angela Papa, Thomas Prokscha, Peter Reiter, Akira Sato, Nathal Severijns, Toni Shiroka, Michael Seidlitz, Stergiani Marina Vogiatzi, Chennan Wang, Frederik Wauters, Nigel Warr, Alex Amato
Summary: A knob bow fibula of the Leutkirch type was excavated in 2018 in Switzerland and analyzed for its elemental composition. The fibula was made of bronze and consisted of two workpieces, with one being cast bronze and the other being forged bronze. The main elements in the fibula were copper, zinc, tin, and lead.
Article
Anthropology
Beda A. Hofmann, Sabine Bolliger Schreyer, Sayani Biswas, Lars Gerchow, Daniel Wiebe, Marc Schumann, Sebastian Lindemann, Diego Ramirez Garcia, Pierre Lanari, Frank Gfeller, Carlos Vigo, Debarchan Das, Fabian Hotz, Katharina von Schoeler, Kazuhiko Ninomiya, Megumi Niikura, Narongrit Ritjoho, Alex Amato
Summary: A search for meteoritic iron artefacts in the Lake of Biel area in Switzerland has led to the identification of a single object, an arrowhead, with meteoritic origin. The object's elemental composition, mineralogy, and presence of cosmogenic 26Al provide strong evidence for its meteoritic nature. This discovery is significant for understanding the use and distribution of meteoritic iron in ancient societies.
JOURNAL OF ARCHAEOLOGICAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Ziga Gosar, Tina Arh, Kevin Jaksetic, Andrej Zorko, Wenhao Liu, Hanlin Wu, Chennan Wang, Hubertus Luetkens, Bing Lv, Denis Arcon
Summary: Quasi-one-dimensional electron systems exhibit instability towards long-range ordered phases at low temperatures. In this study, muon spin rotation and relaxation (& mu;SR) were used to investigate the superconducting state in Rb2Mo3As3, which has one of the highest critical temperatures Tc = 10.4 K among quasi-one-dimensional superconductors. The results show stronger damping below Tc due to the formation of a vortex lattice. Comparison of different models suggests that the s-wave scenario provides the best fit, but with an anomalously small superconducting gap ⠁0/Tc ratio of 2 ⠁0/kBTc = 2.74(1). However, the nodal p-wave or d-wave scenarios cannot be ruled out based on slightly worse fits, yielding more realistic ratios of 2 ⠁0/kBTc = 3.50(2) and 2 ⠁0/kBTc = 4.08(1), respectively.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Chemistry, Multidisciplinary
Lama Khalil, Cyrine Ernandes, Jose Avila, Adrien Rousseau, Pavel Dudin, Nikolai D. Zhigadlo, Guillaume Cassabois, Bernard Gil, Fabrice Oehler, Julien Chaste, Abdelkarim Ouerghi
Summary: In this study, we demonstrate the stable growth of p-type hexagonal boron nitride (h-BN) by using Mg atoms as substitutional impurities. Our experiments involving micro-Raman spectroscopy, nano-ARPES, and KPFM show that Mg-doping significantly alters the electronic properties of h-BN. The Mg dopants shift the valence band maximum and result in a reduced Fermi level difference between pristine and Mg-doped h-BN crystals. This research establishes Mg-doping as a promising method for high-quality p-type doped h-BN films, which are crucial for applications in deep ultraviolet LEDs and wide bandgap optoelectronic devices.
NANOSCALE ADVANCES
(2023)
Article
Physics, Multidisciplinary
Jonathan Frassineti, Pietro Bonfa, Giuseppe Allodi, Erick Garcia, Rong Cong, Brenden R. Ortiz, Stephen D. Wilson, Roberto De Renzi, Vesna F. Mitrovic, Samuele Sanna
Summary: The recently discovered vanadium-based Kagome metals AV3Sb5 exhibit a unique phase transition into charge-density wave (CDW) order that occurs before unconventional superconductivity and time-reversal symmetry breaking. To understand the role of CDW in establishing these unconventional phases, it is crucial to unveil the symmetries and microscopic nature of the charge-ordered phase. In this study, the exact structure of the charge-density wave ordering temperature (TCDW) below RbV3Sb5 is determined through a comprehensive set of nuclear magnetic resonance (NMR) measurements and density functional theory simulations. The findings provide important guidance for developing a theoretical framework to predict properties of exotic electronic orders within the CDW phase.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Chanhyeon Lee, Suheon Lee, Youngsu Choi, C. Wang, H. Luetkens, T. Shiroka, Zeehoon Jang, Young-Gui Yoon, Kwang-Yong Choi
Summary: We used various measurements, including magnetic susceptibility, muon-spin relaxation, and nuclear magnetic resonance, to study the spin dynamics of the quantum spin liquid candidate H3LiIr2O6. We identified two characteristic temperatures, Tg = 110 K and T* = 26 K, through analysis of the relaxation rates. Below Tg, there were distinct components of slower relaxation rate governed by gapped excitations and faster relaxation rate related to gapless excitations. We observed divergent magnetic susceptibility, power-law dependence of relaxation rate on temperature, and weakly activated behavior, indicating the coexistence of a disordered spin-liquid state and spin singlets with distributed gaps.
Article
Materials Science, Multidisciplinary
Vadim Grinenko, Rajib Sarkar, Shreenanda Ghosh, Debarchan Das, Zurab Guguchia, Hubertus Luetkens, Ilya Shipulin, Aline Ramires, Naoki Kikugawa, Yoshiteru Maeno, Kousuke Ishida, Clifford W. Hicks, Hans-Henning Klauss
Summary: Muon spin rotation/relaxation (μSR) and polar Kerr effect measurements provide evidence for a time-reversal symmetry breaking (TRSB) superconducting state in Sr2RuO4. However, the absence of a cusp in the superconducting transition temperature (Tc) vs stress and the absence of a resolvable specific heat anomaly at TRSB transition temperature (TTRSB) under uniaxial stress challenge a hypothesis of TRSB superconductivity. Recent μSR studies under pressure and with disorder indicate that the splitting between Tc and TTRSB occurs only when the structural tetragonal symmetry is broken. To further test such behavior, we measured Tc through susceptibility measurements and TTRSB through μSR, under uniaxial stress applied along a (110) lattice direction. We have obtained preliminary evidence for suppression of TTRSB below Tc, at a rate much higher than the suppression rate of Tc.
