Article
Materials Science, Multidisciplinary
Takashi Tayama, Yusuke Kani, Momota Imai, Yuta Kanai, Hitoshi Sugawara
Summary: The results of magnetization, thermal expansion, and magnetostriction measurements of CeOs4Sb12 reveal magnetic anisotropy and phase differences in the ordered phases A, B, and C. The magnetization at low temperatures in high magnetic fields shows significant anisotropy, with the ratio M[100] > M[110] > M[111] consistent with the xe002;67 quartet. The comparison between experimental results and numerical calculations suggests that the C phase is an antiferroquadrupolar ordered state, mainly influenced by antiferro-octupolar interaction.
Article
Physics, Multidisciplinary
Satoru Hayami, Kazumasa Hattori
Summary: This study investigates the mechanism of multiple-q states consisting of magnetic dipole and electric quadrupole degrees of freedom in classical spin-1 triangular-lattice systems. The researchers find that minimum conditions of multipole interactions can lead to the multiple-q instability even without single-ion magnetic anisotropy and higher-order mode-mode couplings. Six types of triple-q states with various magnetic dipole and electric quadrupole configurations are presented depending on the model parameters, indicating the interplay between dipole and quadrupole degrees of freedom provides another source of rich multiple-q states.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Sreekar Voleti, Koushik Pradhan, Subhro Bhattacharjee, Tanusri Saha-Dasgupta, Arun Paramekanti
Summary: In this study, the dual influence of impurity probes in cubic osmate double perovskites was explored. The impurities were found to induce local strain fields, suppressing the octupolar order while exposing the hidden order parameter. This work provides important implications for uncovering hidden order in diverse multipolar materials.
NPJ QUANTUM MATERIALS
(2023)
Article
Multidisciplinary Sciences
Nikolaj Roth, Andrew L. Goodwin
Summary: Hidden local order in disordered crystals has a strong impact on electronic and phononic band structures. Local correlations within hidden-order states can open band gaps and change material properties without long-range symmetry breaking. Understanding the importance of hidden order for material properties is crucial, as it offers a new mechanism for tuning material properties orthogonal to conventional structure/property relationships.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Florian Otterpohl, Peter Nalbach, Michael Thorwart
Summary: In this study, we investigate the dynamics of a quantum two-level system immersed in a sub-Ohmic bath. By numerical simulations, we find that the system exhibits aperiodic behavior in the strong coupling regime.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
G. Krieger, L. Martinelli, S. Zeng, L. E. Chow, K. Kummer, R. Arpaia, M. Moretti Sala, N. B. Brookes, A. Ariando, N. Viart, M. Salluzzo, G. Ghiringhelli, D. Preziosi
Summary: The electronic and magnetic excitations and charge density correlations in Nd1-xSrxNiO2 thin films were studied, with and without a SrTiO3 capping layer. Dispersing magnons were observed only in the capped samples, progressively dampened with higher doping. An elastic resonant scattering peak similar to the charge order signal in hole-doped cuprates was detected in the uncapped x=0 compound, which weakens with doping and disappears in the superconducting x=0.20 film.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
S. Andreev
Summary: The paper discusses quantum phase transitions in a system of bright dipolar excitons. It reveals that at sufficiently large density, an exciton superfluid transforms into a superfluid of biexcitons, accompanied by a reduction in photoluminescence intensity. The formation of a BCS-like biexciton condensate induces correlated alignment of the effective magnetic fields and excitonic spins, presenting important differences from the phenomenon of spin-orbit-coupled Bose-Einstein condensation.
Article
Chemistry, Multidisciplinary
Andrii Shcherbakov, Kevin Synnatschke, Stanislav Bodnar, Jonathan Zerhoch, Lissa Eyre, Felix Rauh, Markus W. Heindl, Shangpu Liu, Jan Konecny, Ian D. Sharp, Zdenek Sofer, Claudia Backes, Felix Deschler
Summary: Layered van der Waals (vdW) antiferromagnets with low-dimensional excitonic properties and complex spin-structure are promising materials for future opto-spintronic applications. In this study, we successfully fabricated centimeter-scale thin films of the 2D antiferromagnetic material NiPS3 using liquid phase exfoliation. The films showed antiferromagnetic spin arrangement, spin-entangled Zhang-Rice multiplet excitons, and ultranarrow emission line widths, despite their disordered nature. These results demonstrate the scalable thin-film fabrication of high-quality NiPS3, which is crucial for utilizing this material in spintronic and nanoscale memory devices and exploring its complex spin-light coupled states.
Article
Materials Science, Multidisciplinary
Galbadrakh Dagvadorj, Michal Kulczykowski, Marzena H. Szymanska, Michal Matuszewski
Summary: The study reveals the existence of two critical points in the phase diagram of a two-dimensional driven-dissipative system of polaritons, corresponding to quasicondensation and a first-order phase transition from a nonuniform state to a uniform state. The first-order nature of the transition is evidenced by discontinuity in density and correlation length, as well as phase coexistence and metastability. Additionally, a Berezinskii-Kosterlitz-Thouless-like transition signature is observed in the nonuniform phase.
Article
Physics, Multidisciplinary
Yuan Yuan, Hui Chen
Summary: Ghost imaging is an unconventional imaging method that retrieves the image of an object by correlating known illumination patterns with reflected intensity. A new scheme is proposed to enable non-invasive imaging of objects through turbid media without the need for prior knowledge of object patterns. It also overcomes the challenges of imaging through turbid media.
NEW JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Physical
Alexander Thoeny, Iside S. Parrichini, Tobias M. Gasser, Thomas Loerting
Summary: This study investigates the hydrogen substructure of deuterated and deuterium chloride (DCI)-doped ice VI samples and explores the transitions associated with rearrangement of D-atoms in ice XIX using Raman spectroscopy. The study reveals a complex cascade of processes involving the ordering and disordering of D atoms, with ice XIX transitioning to ice VI double dagger and ultimately forming ice XV. The kinetics of ice XIX decay and ice XV build-up are determined using time-resolved Raman spectroscopy, and kinetic models for the phase fractions in non-isothermal heating experiments are proposed based on the experimental data.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Nuclear
Roman Poberezhnyuk, Oleh Savchuk, Mark Gorenstein, Volodymyr Vovchenko, Horst Stoecker
Summary: General formulas for higher order cumulants of conserved charge statistical fluctuations inside the mixed phase are presented, using the van der Waals model in the grand canonical ensemble. The calculations of higher order measures of conserved charge fluctuations near the critical point show that even-order measures have only positive values in the mixed phase and go to infinity, while odd-order measures have regions of positive and negative values near the binodals. These results are discussed in the context of event-by-event fluctuation measurements in heavy-ion collisions.
Article
Physics, Multidisciplinary
Miles I. Collins, Francesco Campaioli, Murad J. Y. Tayebjee, Jared H. Cole, Dane R. McCamey
Summary: Singlet fission refers to the production of two triplet excitons from one singlet exciton while conserving spin. Although the presence of a spin-2 (quintet) triplet-pair state resulting from singlet fission is well established, the exact mechanism for quintet formation has not been determined, making the design of materials for optimal quintet formation challenging. In this study, the authors propose a mechanism in which fluctuations in inter-triplet exchange coupling drive rapid and efficient quintet formation. They demonstrate that quintet formation is feasible even in the strong-exchange regime, consistent with recent experimental predictions. Evaluating the performance of this quintet formation mechanism under different conformational freedom scenarios, the authors establish a connection between quintet dynamics and material properties of singlet fission molecules.
COMMUNICATIONS PHYSICS
(2023)
Review
Chemistry, Multidisciplinary
Sheng Liu, Iftikhar Ahmed Malik, Vanessa Li Zhang, Ting Yu
Summary: 2D magnets, with their atomic-scale thickness, have attracted great attention since their emergence in 2017. These materials possess strong magnetic anisotropy, switchable magnetic order, and quantum-confined quasiparticles, which differentiate them from conventional 3D magnetic materials. Additionally, their 2D geometry allows for easy light incidence and potential on-chip integration. This review focuses on the recent research advancements in light-spin interactions in 2D magnets and discusses the potential design of novel opto-spintronic applications based on these interactions.
ADVANCED MATERIALS
(2023)
Letter
Materials Science, Multidisciplinary
Xingyu Ji, Yun Zhang, Xiaoying Wang, Yi Liu
Summary: The study demonstrates power-law behavior in the electrical resistivity, magnetic susceptibility, and specific heat of high-quality URu2Si2 single crystals in the hidden-order region, consistent with the Griffiths model. The Griffiths phase is characterized by residual short-range correlations on the collapse of the long-range large-moment antiferromagnetic phase, with evidence of cluster-like spins.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Multidisciplinary
Utkarsh Mishra, R. Jafari, Alireza Akbari
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2020)
Article
Multidisciplinary Sciences
Damianos Chatzopoulos, Doohee Cho, Koen M. Bastiaans, Gorm O. Steffensen, Damian Bouwmeester, Alireza Akbari, Genda Gu, Jens Paaske, Brian M. Andersen, Milan P. Allan
Summary: By using scanning tunneling microscopy (STM), dispersive in-gap states in the iron-based superconductor FeTe0.55Se0.45 were found and characterized, along with the discovery of YSR-type impurity states. The use of a superconducting STM tip allowed for enhanced energy resolution and the tuning of impurity states through the Fermi level. The experimental data was well explained by modeling the tip-gating scenario within the single-impurity Anderson model.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Alireza Akbari, Peter Thalmeier
Summary: Research suggests that a spin resonance may still occur in f-electron heavy fermion superconductors even when a fully gapped state is observed at low temperatures. The study shows that resonance can also appear in the fully gapped state for a two-dimensional hybridized superconductor with an unconventional nodal gap function.
Article
Physics, Condensed Matter
Mehdi Biderang, Mohammad-Hossein Zare, Alireza Akbari
Summary: The breakdown of spatial inversion symmetry in noncentrosymmetric materials leads to two different types of electron hopping, both spin-independent and spin-dependent. This spin-dependent term can be interpreted as a quasi-spin-orbit coupling which affects the electronic structure. In locally noncentrosymmetric crystals with sublattice degrees of freedom, there is a distinction between inter- and intra-sublattice hopping integrals, leading to symmetric and antisymmetric quasi-spin-orbit couplings, with consequences on the electronic band structure.
EUROPEAN PHYSICAL JOURNAL B
(2021)
Article
Materials Science, Multidisciplinary
S. Sarkar, F. Cossu, P. Kumari, A. G. Moghaddam, A. Akbari, Y. O. Kvashnin, I Di Marco
Summary: This work presents an ab-initio computational study on the electronic and magnetic properties of transition metal adatoms on a monolayer of NbSe2. It is found that Cr, Mn, Fe, and Co preferentially sit above the Nb atom, leading to strong hybridization with the d states. The inter-atomic exchange coupling exhibits oscillatory behavior accompanied by exponential decay, consistent with the theory for a damped Ruderman-Kittel-Kasuya-Yosida interaction. The results suggest that the magnetic coupling of the investigated adatoms is connected to the fine details of their Fermi surface.
Article
Physics, Condensed Matter
Alireza Akbari, Peter Thalmeier
Summary: We investigate the magnetic excitation spectrum in the helical state of a noncentrosymmetric superconductor with inversion symmetry breaking and strong Rashba spin-orbit coupling. We show that the dynamical susceptibility in this state exhibits typical correlated anisotropies in real space and spin space, which can be observed as a characteristic fingerprint in inelastic neutron scattering investigations.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Harun Al Rashid, Garima Goyal, Alireza Akbari, Dheeraj Kumar Singh
Summary: We studied the temperature dependence of quasiparticle interference in high Tc-superconductors using an exact-diagonalization + Monte-Carlo based scheme. At lower temperatures, the interference patterns were largely influenced by the scattering vectors of the octet model. Our findings indicate that in the pseudogap region of the phase diagram, the features of quasiparticle interference are also dominantly determined by the scattering vectors belonging to the octet model, due to the persisting antinodal gap beyond the superconducting transition Tc. However, when the antinodal gap becomes very small at a certain temperature, a different set of scattering vectors are responsible for the quasiparticle interference patterns. With increasing temperature, the interference patterns become increasingly broadened.
SCIPOST PHYSICS CORE
(2023)
Article
Materials Science, Multidisciplinary
Alireza Akbari, Burkhard Schmidt, Peter Thalmeier
Summary: We investigate the dispersion of dispersive paramagnetic excitons on the honeycomb lattice originating from the crystalline electric field split localized f-electron states in the paramagnetic state due to intersite exchange. We analyze the possible models and calculate the closed expressions for the magnetic exciton dispersion using both response function formalism and bosonic Bogoliubov approach. By calculating the Berry curvatures and Chern numbers of paramagnetic excitons, we show that one of the models supports nontrivial topological states with excitonic topological edge states with Dirac dispersion lying in the zone boundary gap without the presence of magnetic order.
Article
Materials Science, Multidisciplinary
Peter Thalmeier, Alireza Akbari
Summary: The dynamical magnetic response functions in the Fulde-Ferrell (FF) state of a superconductor with inversion symmetry are derived. The segmentation into paired and unpaired regions due to the finite q is observed in the resulting quasiparticle states and spectral functions. The dynamical magnetic susceptibility is calculated in linear response formalism and both quasiparticle excitations inside and between paired and unpaired segments contribute to the dynamical response. The dependence on frequency and momentum transfer is discussed, as well as the possible influence on Knight shift and spin resonance formation.
Article
Physics, Multidisciplinary
Alireza Akbari, Peter Thalmeier
Summary: We investigate the quasiparticle excitations in a Fulde-Ferrell-type helical state of a superconductor with inversion symmetry breaking and strong Rashba spin-orbit coupling. We derive the dependence of quasiparticle dispersions on the Rashba coupling strength and external field, leading to a peculiar segmentation of the corresponding Rashba Fermi surface sheets in momentum space. The method of quasiparticle interference is used to visualize the segmented sheets and map their evolution with field strength, bias voltage, and Rashba coupling. Additionally, we propose a strategy for determining the finite Cooper-pair momentum from experimental quantities.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
R. Jafari, Alireza Akbari, Utkarsh Mishra, Henrik Johannesson
Summary: This study investigates the behavior of a generic class of fermionic two-band models under synchronized periodic driving, showing that synchronized driving can lead to nonperiodic patterns of dynamical quantum phase transitions. The research proposes a method for experimental verification of these transitions.
Article
Optics
J. Naji, Masoud Jafari, R. Jafari, Alireza Akbari
Summary: This study investigates Floquet dynamical phase transitions in dissipative systems, revealing that phase transitions can still occur in the presence of dissipation without the necessity of non-Hermitian topological phases. The range of driven frequency for dissipative FDPTs narrows down with increasing dissipation coupling, eventually shrinking to a single point at the critical value of dissipation, demonstrating the topological characteristic features of dissipative FDPTs in the real gap region.
Article
Materials Science, Multidisciplinary
Peter Thalmeier, Alireza Akbari
Summary: The passage discusses the protected helical surface states in thin films of topological insulators and the appearance of one-dimensional bound states and Majorana zero modes when a step is introduced in the film.
Article
Materials Science, Multidisciplinary
Mehdi Biderang, Alireza Akbari, Jesko Sirker
Summary: This study investigates the electronic properties of transition metal oxides with antisymmetric spin-orbit coupling using a two-dimensional Hubbard model. It reveals that specific charge and magnetic order effects occur under certain doping and bond angle conditions. Comparisons with resonant inelastic x-ray scattering data show qualitative agreement, indicating the model's validity.
Article
Optics
R. Jafari, Alireza Akbari
Summary: This study investigates pure and mixed state Floquet dynamical quantum phase transitions in a one-dimensional p-wave superconductor with a time-driven pairing phase. It is found that FDQFTs occur within a certain range of driving frequency and in the resonance regime of quasispins. The results show that the entanglement spectrum and purity entanglement measure can capture the conditions and features of FDQFTs.
