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We investigate the onset of quantum thermalization in a system governed by the Jahn-Teller Hamiltonian, which describes the interaction between a single spin and two bosonic modes. We find that the Jahn-Teller model exhibits a finite-size quantum phase transition between the normal phase and two types of super-radiant phase when the ratios of spin-level splitting to each of the two bosonic frequencies grow to infinity. We test the prediction of the eigenstate thermalization hypothesis in the Jahn-Teller model. We show that the expectation value of the spin observable quickly approaches its long-time average value. We find that the distance between the diagonal ensemble average and the microcanonical ensemble average of the spin observable decreases with the effective thermodynamic parameter. Furthermore, we show that the mean time fluctuations of the spin observable are small and are inversely proportional to the effective system dimension.
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http://dx.doi.org/10.1103/PhysRevE.110.044127 | DOI Listing |
Inorg Chem
September 2025
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
The nominally trigonal, pseudo-Jahn-Teller (PJT)-active, = 1/2 N-bound complexes, , M = Fe, Co, with three in-plane phosphine ligands and axial donors, E = Si, B, C, include functional nitrogenase models that catalyze the reduction of N to NH. We applied EPR, P ENDOR spectroscopy, and DFT computations to characterize the PJT-induced distortions of four selected , revealing how the metal ion and axial ligand E together tune both PJT dynamics, as revealed by P ENDOR and N activation, as indicated by a decrease in N≡N stretching frequency, ν(N≡N). , and each exhibit a single P isotropic hyperfine coupling, revealing dynamic pseudorotation of the PJT distortion, producing averaged symmetry with equivalent phosphine ligands.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
School of Materials and Energy, Southwest University, Chongqing, 400715, China.
Sodium-ion batteries (SIBs) have emerged as promising energy storage solutions due to resource abundance and low cost, yet their practical deployment is hindered by limited operating voltages of cathode materials. Herein, we propose a universal ligand-field engineering strategy to enhance voltage through electronic structure modulation in transition metal oxides. Using the NaMgMnO as a model system, weak-field ligands are introduced to alter the coordination environment of MnO octahedra.
View Article and Find Full Text PDFAdv Mater
August 2025
Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762, USA.
The spin-orbit coupling (SOC) and the Jahn-Teller effect (JTE) alter the orbital degeneracy in materials, leading to unique optical, electronic, and magnetic properties essential in spintronics, quantum computing, and light-emitting diodes (LEDs). Here, the study employs luminescent p-xylylenediammonium (PXA) instead of Cs in CsNaInCl to yield 2D Sb-doped (PXA)NaInCl double perovskite and demonstrates a non-degenerate triplet state resulting from enhanced JTE in the strong SOC regime, featuring distinct emission centers. Consequently, a broadband emission from both PXA and [SbCl] spans the entire spectrum (350-750 nm), representing a rare single-source multi-emissive 2D perovskite.
View Article and Find Full Text PDFSci Rep
August 2025
Physics Department, Faculty of Science, Sohag University, Sohag, 82524, Egypt.
The current study presents an unprecedented detailed investigation of the structural, magnetic, electrical, molecular, morphological and compositional analysis of the LaSrMnCoO (LSMCO) nanoparticles synthesized by the sol-gel method and calcinated at 650, 1000, and 1100 °C. Rietveld refinements and FTIR analysis, confirmed the formation of perovskite structure, where Rietveld output was used to trace the effect of calcination temperature on the overall structural properties. The Jahn-Teller distortion in LSMCO was inferred from the rhombohedral distortion, cooperative octahedral tilting/canting, electron distribution density, and shifts in Mn-O bond absorbance.
View Article and Find Full Text PDFPhys Rev Lett
July 2025
Inner Mongolia University, School of Physical Science and Technology, and Inner Mongolia Key Laboratory of Microscale Physics and Atom Innovation, Hohhot 010021, China.
Achieving effective manipulation of perpendicular magnetic anisotropy within the coupling of ferroelectricity remains an intricate challenge, yet it is crucial in the electric-field control of the excitation and propagation of magnonic spin-polarization currents. Perpendicularly magnetized structures are normally inhibited to varying degrees in a polarization switching path due to the intrinsic chemical incompatibility of electronic mechanisms for single-phase multiferroics. Here, we demonstrate a geometrically coupling strategy of oxygen octahedral distortions to regulate hybrid improper ferroelectricity and perpendicular magnetic anisotropy coupled in double-perovskite superlattice films.
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