Interplay of superexchange and vibronic effects in the hidden order of Ba${}_2$MgReO${}_6$ from first principles

Abstract

The origin of the "hidden" quadrupolar and unconventional magnetic low-temperature orders observed in the spin-orbit double perovskite Ba${}_2$MgReO${}_6$ defies explanation through standard experimental and theoretical techniques. Here we address this problem by deriving and solving an ab initio low-temperature effective Hamiltonian including inter-site electronic exchange and vibronic (electron-lattice) couplings between $J_{eff}=3/2$ Jahn-Teller-active Rhenium states. Our findings disclose the nature of these elusive states, attributing it to intertwined exchange and electron-lattice couplings, thus diverging from the conventional dichotomy of purely electronic or lattice driving mechanisms. Our results indicate the resilience of the quadrupolar hidden order under pressure, yet its rapid suppression under uniaxial strain suggests that external or lattice-induced distortions play a pivotal role in determining the relative stability of competing phases in Ba${}_2$MgReO${}_6$ and similar $d^1$ double perovskites.

6 pages + 18 pages of Supplementary, 4 Figures

References in corpus (18)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Implementation strategies in phonopy and phono3py
• First direct observation of Dirac fermions in graphite
• Dynamical Mean-Field Theory within an Augmented Plane-Wave Framework: Assessing Electronic Correlations in the Iron Pnictide LaFeAsO
• Spin-orbit-entangled electronic phases in 4$d$ and 5$d$ transition-metal compounds
• Novel Magnetism and Local Symmetry Breaking in a Mott Insulator with Strong Spin Orbit Interactions
• Detection of multipolar orders in the spin-orbit-entangled 5d Mott insulator Ba2MgReO6
• Ferro-octupolar order and low-energy excitations in d${}^2$ double perovskites of Osmium
• Interplay between multipolar spin interactions, Jahn-Teller effect and electronic correlation in a $J_{eff}=\frac{3}{2}$ insulator
• Untangling the structural, magnetic dipole, and charge multipolar orders in Ba${}_2$MgReO${}_6$
• Phase transition in the 5d1 double perovskite Ba2CaReO6 induced by high magnetic field
• Vibronic order and emergent magnetism in cubic $d^1$ double perovskites
• Possible quadrupole order in tetragonal Ba2CdReO6 and chemical trend in the ground states of 5d1 double perovskites
• Interplay between quadrupolar and magnetic interactions in 5$d^1$ double perovskite Ba${}_2$MgReO${}_6$ under pressure
• Structure, heat capacity and Raman spectra of mm-sized Ba${}_2$MgWO${}_6$ single crystals synthesized by BaCl${}_2$-MgCl${}_2$ flux method
• Multipolar interactions and magnetic excitation gap in d${}^3$ spin-orbit Mott insulators
• Electronic origin of ferroic quadrupole moment under antiferroic quadrupole orders and finite magnetic moment in $J_{\mathrm{eff}}=3/2$ systems
• Efficient Method for Prediction of Meta-stable/Ground Multipolar Ordered States and its Application in Monolayer $\alpha$-\ce{RuX3} (X=Cl,I)

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• Dipolar and quadrupolar correlations in the $5d^2$ Re-based double perovskites Ba${}_2$YReO${}_6$ and Ba${}_2$ScReO${}_6$
• Coupled-cluster approach to vibronic effects in resonant inelastic x-ray scattering of quantum materials: Application to a $5d^1$ rhenium oxide
• Pseudo-chiral phonon splitting from octupolar magnetic order
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