Article
Chemistry, Physical
Sonu Vishvakarma, V Srinivas, D. L. R. Khanna, J. Perez-Landazabal
Summary: The magnetic and thermal properties of Cu-substituted Ni-Cr alloys near their critical concentration were investigated. It was found that compositions below the critical concentration exhibit weak itinerant ferromagnetic character. The magnetization and specific heat data within experimental uncertainties follow the theoretical predictions of a ferromagnetic quantum critical point. The possibility of a quantum Griffiths phase in these alloy compositions was also suggested.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Multidisciplinary Sciences
Istvan A. Kovacs, Ferenc Igloi
Summary: This article investigates the geometrical properties of rare regions in the transverse Ising model and their characteristics in diluted and random models.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Yang Xin, Lei Shi, Jiyin Zhao, Xueyou Yuan, Shiming Zhou, Li Hou, Liping Yang
Summary: The structure and magnetic properties of double perovskite Dy2CoMnO6 (DCMO) were investigated, revealing the existence of a Griffiths phase which differs significantly from non-Griffiths phase behavior. The effects of A-site rare-earth ions on magnetism are dominated by radius, moments, and 3d-4f exchange interactions. FM/AFM coupling is related not only to the outer 4f electrons of rare earth ions, but also to inner orbital electrons.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Ying Xing, Yiyu Liu, Pu Yang, Jun Ge, Longxin Pan, Junyan Wang, Shichao Qi, Yi Liu, Jian Wang
Summary: Researchers reported the magnetic field induced superconductor-metal transition phenomenon in 4Ha-TaSe2 nanodevices, and observed the quantum Griffiths singularity in its thin films. As the thickness of the nanodevices increased, the signature of magnetoresistance crossing region could hardly be detected, revealing the thickness dependence of the transition phenomenon.
Article
Materials Science, Multidisciplinary
Yingcheng Zhao, Yueqi Su, Yuqiao Guo, Jing Peng, Jiyin Zhao, Chenyang Wang, Linjun Wang, Changzheng Wu, Yi Xie
Summary: In this study, Quantum Griffiths singularity (QGS) was triggered in organic-inorganic hybrid superlattices through the introduction of large-sized organic cations into layered inorganic crystals. The charge transfer introduced charge disorder into the hybrid superlattice without destroying lattice integrity, resulting in the emergence of QGS in bulk superconductors. The deviation of the phase boundary from the Werthamer-Helfand-Hohenberg theory suggests relatively strong spin-orbit coupling and provides a new pathway to investigate quantum phase transitions in disordered systems.
ACS MATERIALS LETTERS
(2021)
Article
Multidisciplinary Sciences
T. M. Wintermantel, M. Buchhold, S. Shevate, M. Morgado, Y. Wang, G. Lochead, S. Diehl, S. Whitlock
Summary: This study reveals a striking correspondence between the excitation dynamics of a laser-driven gas of Rydberg atoms and the spreading of diseases, providing a controllable platform for studying non-equilibrium dynamics on complex networks. The growth of excitation number in epidemics is found to be sub-exponential and a quantitative microscopic susceptible-infected-susceptible model is developed based on this observation. Physical insights into non-equilibrium criticality and non-universal power-laws in the dynamics of complex systems are provided.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Tran Dang Thanh, Nguyen Van Quynh, Tran Thi Ngoc Nha, Pham Hong Nam, Do Hung Manh, Pham Thanh Phong
Summary: The magnetic behavior of La0.7Sr0.3Mn0.95Fe0.05O3 nanoparticles was studied, and it was found that the sample exhibited a ferromagnetic-paramagnetic transition at around 290K, with the presence of a Griffiths phase. The obtained critical exponents were distinct from known universality classes, indicating the unconventional behavior attributed to the Griffiths phase.
Article
Physics, Applied
Zihan Cui, Longxin Pan, Jingchao Fang, Shichao Qi, Ying Xing, Haiwen Liu, Yi Liu, Jian Wang
Summary: The quantum Griffiths singularity (QGS) is a phenomenon characterized by the divergence of the dynamical critical exponent with the activated scaling law, and it has been observed in various two-dimensional superconductors. Recent research has shown that the direct activated scaling analysis, combined with the consideration of irrelevant correction, can be applied to the experimental data of different superconducting films, providing new evidence for QGS. This method has been successfully used to analyze the experimental data of crystalline PdTe2, polycrystalline beta-W films, tri-layer Ga films, and LaAlO3/SrTiO3 interface superconductors, and it represents a more direct and precise way to analyze QGS in various two-dimensional superconductors compared to previous methods based on finite size scaling.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Yuesheng Li, Qiao-Yi Li, Wei Li, Tao Liu, David J. Voneshen, Pabitra K. Biswas, Devashibhai Adroja
Summary: The interplay between randomness and quantumness can lead to unique phenomena in strongly correlated materials, such as the quantum Griffiths phase. The compound PrTiNbO6 provides a concrete example of a quantum Griffiths magnet, offering an ideal experimental platform for investigating the dynamical properties of random many-body systems.
NPJ QUANTUM MATERIALS
(2021)
Article
Astronomy & Astrophysics
Ludwig Eglseer, Stefan Hofmann, Marc Schneider
Summary: It is shown that for Schwarzschild black holes, dynamically generated Zeno borders separate local quantum physics from classical information leaks. Beyond these borders, the black-hole interiors become asymptotically silent, with quantum fields evolving freely towards the geodesic singularity, and having vanishing probability measure for populating the geodesic boundary. Zeno borders thus provide a probabilistic completion of Schwarzschild black holes within the semiclassical framework.
Article
Materials Science, Multidisciplinary
Sanchar Sharma, Victor A. S. V. Bittencourt, Alexy D. Karenowska, Silvia Viola Kusminskiy
Summary: Generating nonclassical states in macroscopic systems is a challenging task, and one approach involves using novel hybrid systems based on magnetic dielectrics. In this study, a proposal to generate a magnetization cat state using a conventional setup of a macroscopic ferromagnet in a microwave cavity is presented. The scheme involves utilizing the ground state of an ellipsoid shaped magnet and collapsing the magnetization to a cat state through either a single photon or a parity measurement of the microwave cavity state.
Article
Materials Science, Multidisciplinary
Sopheak Sorn, Arun Paramekanti
Summary: In this study, transport in the presence of magnetic domain walls in a lattice model of ferromagnetic type-I Weyl metals was investigated. The study revealed the effect of DW scattering, particularly a strong skew scattering at the DW near Weyl points leading to a significant additional Hall effect. The findings are potentially relevant for understanding the Hall resistivity of spin-orbit coupled ferromagnetic metals with Weyl points near the Fermi energy, such as Co3Sn2S2, Co2MnGa, and SrRuO3.
Article
Physics, Multidisciplinary
Nils Niggemann, Yasir Iqbal, Johannes Reuther
Summary: This article investigates fracton phases in quantum spin liquids, assesses the impact of quantum fluctuations on their characteristic features, and finds that quantum fluctuations modify the shape of these features, indicating possible fragility of these phases.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Hui Hu, Xia-Ji Liu
Summary: We conducted a systematic study on a mobile impurity immersed in a three-dimensional Fermi sea of fermions at finite temperature. By using the standard non-self-consistent many-body T-matrix theory, we determined the impurity spectral function and avoided potential errors in previous calculations. The results showed that the quasiparticle decay rate of both attractive and repulsive polarons does not increase significantly with increasing temperature in the weak-coupling limit, while near the unitary limit with strong coupling, the decay rate of Fermi polarons rapidly increases and the quasiparticle picture breaks down close to the Fermi temperature.
Article
Materials Science, Multidisciplinary
Li Xiang, Elena Gati, Sergey L. Bud'ko, Scott M. Saunders, Paul C. Canfield
Summary: The pressure-temperature phase diagram of La5Co2Ge3 was constructed up to 5 GPa, showing a change in magnetic behavior and transition to a new low-temperature ground state. This suggests that the ferromagnetic quantum critical point in La5Co2Ge3 is avoided by the appearance of a different, likely magnetically ordered state with an antiferromagnetic component.