Magnetic blue shift of Mott gaps enhanced by double exchange

Hafez-Torbati, Mohsen; Bossini, Davide; Anders, Frithjof B.; Uhrig, Götz S.

doi:10.1103/physrevresearch.3.043232

Cited by 7 publications

(24 citation statements)

References 70 publications

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“…For T < T N the PI is not the stable phase due to the spin ordering but G PI (T ) can still be analyzed by extrapolating the results to below T N in experiment or by enforcing a paramagnetic solution in theory. A magnetic blue shift (MBS) corresponding to Γ MG (T ) > 0 is observed in several previous experimental [12][13][14][15][16][17][18] and theoretical investigations [18][19][20][21][22][23][24] of antiferromagnetic insulators. We unveiled in Ref.…”

Section: Introductionmentioning

confidence: 93%

“…[17] and applied successfully to α-MnTe in Ref. [24]. It is discussed here in details for the sake of completeness.…”

Section: A Hubbard-kondo-heisenberg Modelmentioning

confidence: 99%

“…We applied the method specifically to the HKH model in Ref. [24]. Here, we review the procedure for the sake of completeness.…”

Section: B Dynamical Mean-field Theorymentioning

confidence: 99%

“…Although the DMFT formulated in momentum space is suitable for the current problem we opt for the real-space DMFT [38][39][40] due to its easy adaptability to study the spatial dependence of the MBS in thin films in the future as well as due to the efficient and flexible implementation we have for the method at hand [41] which has been already applied to multiple problems [24,[42][43][44]. The main disadvantage of the real-space DMFT is the finiteness of the system.…”

Section: B Dynamical Mean-field Theorymentioning

confidence: 99%

“…We unveiled in Ref. [24] that the MBS originates from the double exchange and exchange mechanisms. A strong MBS enables to go beyond the local magnetization dynamics [7][8][9] and induce an ultrafast coherent manipulation of the transport properties.…”

Section: Introductionmentioning

confidence: 99%

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A simplified approach to the magnetic blue shift of Mott gaps

Hafez-Torbati¹,

Anders²,

Uhrig³

2022

Preprint

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The antiferromagnetic ordering in Mott insulators upon lowering the temperature is accompanied by a transfer of the single-particle spectral weight to lower energies and a shift of the Mott gap to higher energies (magnetic blue shift, MBS). The MBS is governed by the double exchange and the exchange mechanisms. Both mechanisms enhance the MBS upon increasing the number of orbitals. We provide an expansion for the MBS in terms of hopping and exchange coupling of a prototype Hubbard-Kondo-Heisenberg model and discuss how the results can be generalized for application to realistic Mott or charge-transfer insulator materials. This allows estimating the MBS of the charge gap in real materials in an extremely simple way avoiding extensive theoretical calculations. The approach is exemplarily applied to α-MnTe, NiO, and BiFeO3 and an MBS of about 130 meV, 360 meV, and 157 meV is found, respectively. The values are compared with the previous theoretical calculations and the available experimental data. Our ready-to-use formula for the MBS simplifies the future studies searching for materials with a strong coupling between the antiferromagnetic ordering and the charge excitations, which is paramount to realize a coupled spin-charge coherent dynamics at a femtosecond time scale.

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