Article
Materials Science, Multidisciplinary
E. S. Klyushina, J. Reuther, L. Weber, A. T. M. N. Islam, J. S. Lord, B. Klemke, M. Mansson, S. Wessel, B. Lake
Summary: The study revealed that BaNi2V2O8 behaves as a two-dimensional antiferromagnet across the entire temperature range, with different behavior patterns emerging as the temperature increases. Close to the ordering temperature TN, the system behaves as a 2D XY antiferromagnet, while above TN, evidence of Berezinskii-Kosterlitz-Thouless behavior driven by vortex excitations was observed.
Article
Physics, Multidisciplinary
Feng Xu, Lei Zhang, Liyun Jiang, Chung-Yu Mou
Summary: The study demonstrates that flat-band superconductivity in strained graphene can significantly increase the superconducting transition temperature, while the superfluid weight of pure superconducting pair-density-wave states exhibits a transition temperature much lower than the pair density wave gap-opening temperature.
CHINESE JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
G. Dagvadorj, P. Comaron, M. H. Szyma
Summary: We investigate a four-component polariton system in the optical parametric oscillator regime and find that all four components exhibit the same BKT critical point and algebraic decay of spatial coherence. However, the creation of topological defects near the phase transition is largely independent of intercomponent mode locking and strongly depends on the density within a given mode. This unique characteristic allows us to discover a novel state of matter characterized by the proliferation of topological defects on a superfluid with algebraic decay of coherence, which can be observed in current experiments.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
I Garcia-Mata, J. Martin, O. Giraud, B. Georgeot, R. Dubertrand, G. Lemarie
Summary: This study demonstrates that the Anderson transition in random graphs displays the same type of flow as the many-body localization (MBL) transition. It shows that the wave functions have a larger localization length in the longitudinal direction than in the perpendicular direction. This finding is important for understanding the localization phenomenon and the MBL transition.
Letter
Chemistry, Multidisciplinary
Arthur Veyrat, Valentin Labracherie, Dima L. Bashlakov, Federico Caglieris, Jorge I. Facio, Grigory Shipunov, Titouan Charvin, Rohith Acharya, Yurii Naidyuk, Romain Giraud, Jeroen van den Brink, Bernd Buechner, Christian Hess, Saicharan Aswartham, Joseph Dufouleur
Summary: In this study, it is predicted that broken inversion symmetry and strong spin-orbit coupling in trigonal PtBi2 lead to a type-I Weyl semimetal band structure. Transport measurements reveal unusually robust low dimensional superconductivity in thin exfoliated flakes of PtBi2, with thickness up to 126 nm and critical temperature (T-c) ranging from 275-400 mK. A Berezinskii-Kosterlitz-Thouless transition with critical temperature (T-BKT) around 310 mK is observed in up to 60 nm thick flakes, which is significantly thicker than rare examples of two-dimensional superconductors exhibiting such a transition. PtBi2 thus provides an ideal platform to study low dimensional and unconventional superconductivity in topological semimetals.
Article
Physics, Multidisciplinary
D. Opherden, M. S. J. Tepaske, F. Baertl, M. Weber, M. M. Turnbull, T. Lancaster, S. J. Blundell, M. Baenitz, J. Wosnitza, C. P. Landee, R. Moessner, D. J. Luitz, H. Kuehne
Summary: We report the manifestation of field-induced Berezinskii-Kosterlitz-Thouless (BKT) correlations in the weakly coupled spin-1/2 Heisenberg layers of the molecular-based bulk material. The application of laboratory magnetic fields induces a substantial XY anisotropy of the spin correlations, providing a significant BKT regime. We use nuclear magnetic resonance measurements and quantum Monte Carlo simulations to probe and study the spin correlations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Zhiyao Zuo, Shuai Yin, Xuanmin Cao, Fan Zhong
Summary: In this study, a series of scaling theories for Kosterlitz-Thouless phase transitions are proposed and verified using a one-dimensional Bose-Hubbard model, improving upon commonly used scaling assumptions and presenting finite-size and finite-entanglement scaling forms. The results show that the rate exponent varies with the distance from the critical point and driving rate, consistent with experimental findings, and that the finite-size and finite-entanglement scaling can well describe the experimental results.
Article
Chemistry, Physical
Wen-He Jiao, Xiao-Feng Xu, Hao Jiang, Zhu-An Xu, Qing-Hu Chen, Guang-Han Cao
Summary: The study demonstrates the presence of BKT transition and Nelson-Kosterlitz jump in high-quality Ba(Fe0.914Co0.086)(2)As-2 single crystals, along with a non-Hall transverse signal exactly at the superconducting transition, which is likely attributed to the guided motion of unbound vortices.
Article
Materials Science, Multidisciplinary
Fernando Gomez-Ortiz, Pablo Garcia-Fernandez, Juan M. Lopez, Javier Junquera
Summary: We investigated the emergence of Berezinskii-Kosterlitz-Thouless (BKT) phases in (PbTiO3)3/(SrTiO3)3 superlattices using second-principles simulations. Under a tensile epitaxial strain of e = 0.25-1%, the local dipole moments within the superlattices are confined to the film-plane, leading to two-dimensional polarization. Our analysis of dipole-dipole correlation decay, density of defects, and temperature dependence supports the existence of a BKT phase, characterized by quasi-long-range order and the presence of tightly bound vortex-antivortex pairs. This proposed superlattice model can be experimentally verified due to its feasibility in fabrication and the imposed mechanical boundary conditions.
Article
Crystallography
Michal Marek Pilch, Christian Rodenbuecher, Franciszek Krok, Kristof Szot
Summary: Our paper investigates the distribution of dopants in lanthanum-doped strontium titanate (LSTO) single crystals. We found a discrepancy between theoretical and experimental densities. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, and selected area diffraction confirmed that the concentration of lanthanum varies significantly on the micro- and nanoscopic scale. Using local conductivity atomic force microscopy measurements, we observed band-like inhomogeneities in the electrical conductivity, which correlated with the distribution of lanthanum.
Article
Materials Science, Multidisciplinary
Y-H Tseng, F-J Jiang
Summary: By using a supervised neural network trained on a one-dimensional lattice, the study successfully calculated the Berezinskii-Kosterlitz-Thouless phase transitions of two-dimensional classical XY models. The neural network approach proved to be accurate in predicting critical points with minimal information and demonstrated efficiency in computation. This universal neural network is not only valid for symmetry breaking related phase transitions, but also for calculating critical points associated with topology.
RESULTS IN PHYSICS
(2022)
Article
Optics
Koichiro Furutani, Andrea Perali, Luca Salasnich
Summary: We theoretically investigate the Berezinskii-Kosterlitz-Thouless transition in a binary mixture of bosonic atoms with Rabi coupling. The transition temperature shows a nonmonotonic behavior with respect to the intercomponent coupling and an amplification for finite Rabi coupling. By developing the Nelson-Kosterlitz renormalization-group equations, we clarify the dependence of the transition temperature on the Rabi coupling and the intercomponent coupling. Our results contribute to the understanding of multicomponent quantum systems, such as multiband superconductors.
Article
Optics
Elahe Samimi, Mohammad Hossein Zarei, Afshin Montakhab
Summary: This paper investigates the global entanglement (GE) and conditional global entanglement (Q) in Kosterlitz-Thouless (KT) phase transitions. It finds that while GE does not indicate clear transition points, Q shows strong signatures of the KT transition points. The study also demonstrates that Q can characterize various phases of the model and behaves differently in each phase.
Article
Multidisciplinary Sciences
Sujit Sarkar
Summary: The BKT mechanism applies not only to conventional many-body systems, but also to strongly correlated PT symmetry quantum criticality. We observe the presence of hidden QBKT and conventional QBKT for the real part of the potential, with no evidence for the imaginary part. Additionally, we provide exact solutions for the RG flow lines.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Kyuho Lee, Bai Yang Wang, Motoki Osada, Berit H. Goodge, Tiffany C. C. Wang, Yonghun Lee, Shannon Harvey, Woo Jin Kim, Yijun Yu, Chaitanya Murthy, Srinivas Raghu, Lena F. Kourkoutis, Harold Y. Hwang
Summary: The occurrence of superconductivity in proximity to strongly correlated phases of matter has sparked interest in understanding the normal state properties that give rise to superconductivity. The recent discovery of superconductivity in layered nickelates has generated similar interest. However, transport measurements of doped infinite-layer nickelate thin films have been limited by material constraints, including a high density of extended defects. By using a substrate that better stabilizes the growth and reduction conditions, we were able to synthesize doped Nd1-xSrxNiO2 films essentially free from extended defects. This allowed us to observe similar normal state resistivity behaviors to the copper oxides, despite key distinctions in their electronic structure and insulating properties.
Article
Physics, Multidisciplinary
A. Stupakiewicz, C. S. Davies, K. Szerenos, D. Afanasiev, K. S. Rabinovich, A. V. Boris, A. Caviglia, A. V. Kimel, A. Kirilyuk
Summary: Researchers have achieved switching of magnetization in magnetic garnet films by ultrafast resonant excitation of longitudinal optical phonon modes, revealing the magneto-elastic mechanism of the switching. In contrast, excitation of strongly absorbing transverse phonon modes results in a thermal demagnetization effect only.
Article
Chemistry, Physical
D. Afanasiev, J. R. Hortensius, B. A. Ivanov, A. Sasani, E. Bousquet, Y. M. Blanter, R. V. Mikhaylovskiy, A. V. Kimel, A. D. Caviglia
Summary: The study demonstrates that light-driven phonons can be utilized to coherently manipulate macroscopic magnetic states. Resonant excitation of phonons allows for rapid and ordered switching of magnetic states.
Article
Multidisciplinary Sciences
Aurore Finco, Angela Haykal, Rana Tanos, Florentin Fabre, Saddem Chouaieb, Waseem Akhtar, Isabelle Robert-Philip, William Legrand, Fernando Ajejas, Karim Bouzehouane, Nicolas Reyren, Thibaut Devolder, Jean-Paul Adam, Joo-Von Kim, Vincent Cros, Vincent Jacques
Summary: By utilizing a quantum magnetometer based on a single NV center, the researchers have successfully demonstrated the all-optical imaging of antiferromagnetic spin textures. Through variations in the NV spin relaxation rate, they were able to image AFM domain walls and skyrmions.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Dedalo Sanz-Hernandez, Maryam Massouras, Nicolas Reyren, Nicolas Rougemaille, Vojtech Schanilec, Karim Bouzehouane, Michel Hehn, Benjamin Canals, Damien Querlioz, Julie Grollier, Francois Montaigne, Daniel Lacour
Summary: Artificially generating advanced functionalities through engineering of internal structure is possible with metamaterials. Artificial spin networks, by tuning the local interaction between elements, offer promising candidates for controlling collective magnetic behavior. By introducing magnetic domain-wall motion within an artificial spin network, a tunable stochastic response can be achieved, opening up new paths towards post-Von Neumann computing architectures such as Bayesian sensing or random neural networks.
ADVANCED MATERIALS
(2021)
Article
Physics, Applied
N. Figueiredo-Prestes, S. Krishnia, S. Collin, Y. Roussigne, M. Belmeguenai, S. M. Cherif, J. Zarpellon, D. H. Mosca, H. Jaffres, L. Vila, N. Reyren, J. -M. George
Summary: In this study, experimental and numerical results were presented to investigate the magnetization reversal induced by spin-orbit torques in micronic disks of a ferromagnetic multilayer. The critical current for complete reversal, as well as the torque ratio and nucleation process, were determined. The experiments and simulations provided insights into the key parameters involved in the magnetization reversal process.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yaqi Li, Edoardo Zatterin, Michele Conroy, Anastasiia Pylypets, Fedir Borodavka, Alexander Bjorling, Dirk J. Groenendijk, Edouard Lesne, Adam J. Clancy, Marios Hadjimichael, Demie Kepaptsoglou, Quentin M. Ramasse, Andrea D. Caviglia, Jiri Hlinka, Ursel Bangert, Steven J. Leake, Pavlo Zubko
Summary: The combination of strain and electrostatic engineering in epitaxial heterostructures of ferroelectric oxides offers possibilities for inducing new phases and enhanced electrical properties. By releasing the mechanical constraint imposed by the substrate, the balance between elastic and electrostatic forces can be altered, activating new mechanical degrees of freedom and resulting in the formation of curved heterostructures.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Martin Lee, Martin P. Robin, Ruben H. Guis, Ulderico Filippozzi, Dong Hoon Shin, Thierry C. van Thiel, Stijn P. Paardekooper, Johannes R. Renshof, Herre S. J. van der Zant, Andrea D. Caviglia, Gerard J. Verbiest, Peter G. Steeneken
Summary: This work demonstrates the use of self-sealing membranes to seal the reference cavity beneath, improving the gas permeation time constant. The adhesion increase over SiO2 is mediated by oxygen bonds that are formed at the SiO2/complex oxide interface during the self-sealing anneal.
Article
Materials Science, Multidisciplinary
Gyanendra Singh, Claudio Guarcello, Edouard Lesne, Dag Winkler, Tord Claeson, Thilo Bauch, Floriana Lombardi, Andrea D. Caviglia, Roberta Citro, Mario Cuoco, Alexei Kalaboukhov
Summary: We present strong experimental indications of unconventional superconductivity in the LaAlO3/SrTiO3 interface through superconducting transport measurements. The observed substantial anomalous enhancement of the critical current by small magnetic fields applied perpendicularly to the plane of electron motion, as well as the asymmetric response with respect to the magnetic field direction, cannot be explained by canonical spin-singlet superconductivity. Our theoretical model, based on the coexistence of Josephson channels with intrinsic phase shifts, describes the experimental observations and excludes a time-reversal symmetry breaking scenario, suggesting the presence of anomalous pairing components compatible with inversion symmetry breaking and multi-orbital physics.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Martin Lee, Johannes R. Renshof, Kasper J. van Zeggeren, Maurits J. A. Houmes, Edouard Lesne, Makars Siskins, Thierry C. van Thiel, Ruben H. Guis, Mark R. van Blankenstein, Gerard J. Verbiest, Andrea D. Caviglia, Herre S. J. van der Zant, Peter G. Steeneken
Summary: This study successfully combines graphene electrodes with free-standing complex oxide, BaTiO3 (BTO), to create ultrathin piezoelectric resonators with variable resonance frequency and ferroelectric memory effect.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Edouard Lesne, Yildiz G. Saglam, Raffaele Battilomo, Maria Teresa Mercaldo, Thierry C. van Thiel, Ulderico Filippozzi, Canio Noce, Mario Cuoco, Gary A. Steele, Carmine Ortix, Andrea D. Caviglia
Summary: In this article, the discovery of Berry curvature (BC) in LaAlO3/SrTiO3 interfaces grown along the [111] direction is reported, which originates from both spin and orbital sources. The BC associated with the spin quantum number is detected through the measurements of an anomalous planar Hall effect. The presence of a nonlinear Hall effect with time-reversal symmetry indicates the existence of large orbital-mediated BC dipoles. The coexistence of different forms of BC allows for the integration of spintronic and optoelectronic functionalities in a single material.
Article
Physics, Multidisciplinary
Mattias Matthiesen, Jorrit R. Hortensius, Samuel Manas-Valero, Itzik Kapon, Dumitru Dumcenco, Enrico Giannini, Makars Siskin, Boris A. Ivanov, Herre S. J. van der Zant, Eugenio Coronado, Alexey B. Kuzmenko, Dmytro Afanasiev, Andrea D. Caviglia
Summary: The research focuses on investigating optical methods for generating coherent magnons in antiferromagnetic insulators. It is found that orbital transitions are key targets for magnetic control in insulators with zero orbital angular momentum.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Maria Teresa Mercaldo, Canio Noce, Andrea D. D. Caviglia, Mario Cuoco, Carmine Ortix
Summary: The Berry curvature (BC), which encodes the geometric properties of electronic wavefunctions, is essential for various Hall-like transport phenomena. This study shows that BC concentrations can arise even without hole excitations in materials with orbital degrees of freedom. The crystals fields in low-symmetric structures trigger BCs characterized by hot-spots and singular pinch points, leading to giant BC dipoles and large non-linear transport responses.
NPJ QUANTUM MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Cyril Leveille, Samuel Flewett, Erick Burgos-Parra, Yanis Sassi, William Legrand, Fernando Ajejas, Vincent Cros, Nicolas Reyren, Nicolas Jaouen
Summary: Recent research has shown that stabilizing noncollinear chiral spin textures in synthetic antiferromagnets (SAFs) can improve device efficiency and stabilize ultrasmall textures, while avoiding transverse deflections. Circular dichroism in x-ray resonant scattering can directly determine the relevant parameters of a magnetic SAF texture, aiding in understanding temperature stability and temperature scaling of exchange interactions.
Article
Materials Science, Multidisciplinary
Samuel Flewett, Erick Burgos-Parra, Mackarena Garrido Strelow, Yanis Sassi, Cyril Leveille, Fernando Ajejas, Nicolas Reyren, Nicolas Jaouen
Summary: This study introduces a numerical algorithm for simulating resonant x-ray magnetic scattering taking into account the magnetization distribution over a multilayer sample, achieving high agreement with experimental data. Incorporating the transmission components into the algorithm was found to be crucial for explaining the dichroism observed in scattering from Bloch-type domain walls.
Article
Materials Science, Multidisciplinary
T. Guillet, A. Marty, C. Vergnaud, M. Jamet, C. Zucchetti, G. Isella, Q. Barbedienne, H. Jaffres, N. Reyren, J-M George, A. Fert
Summary: Research has shown that the Rashba spin-orbit interaction leads to the splitting of spin levels at surfaces and interfaces, generating an effective magnetic field that can be demonstrated through various experimental methods.
