SciPost Physics

SciPost Phys. 6, 027 (2019) · published 5 March 2019

• doi: 10.21468/SciPostPhys.6.3.027
• pdf
• BiBTeX
• RIS
• Submissions/Reports
• 

Abstract

In order to have a better understanding of ultrafast electrical control of exchange interactions in multi-orbital systems, we study a two-orbital Hubbard model at half filling under the action of a time-periodic electric field. Using suitable projection operators and a generalized time-dependent canonical transformation, we derive an effective Hamiltonian which describes two different regimes. First, for a wide range of non-resonant frequencies, we find a change of the bilinear Heisenberg exchange $J_{\textrm{ex}}$ that is analogous to the single-orbital case. Moreover we demonstrate that also the additional biquadratic exchange interaction $B_{\textrm{ex}}$ can be enhanced, reduced and even change sign depending on the electric field. Second, for special driving frequencies, we demonstrate a novel spin-charge coupling phenomenon enabling coherent transfer between spin and charge degrees of freedom of doubly ionized states. These results are confirmed by an exact time-evolution of the full two-orbital Mott-Hubbard Hamiltonian.

• Kartsev et al., Biquadratic exchange interactions in two-dimensional magnets
  npj Comput Mater 6, 150 (2020) [Crossref]
• Quito et al., Floquet Engineering Correlated Materials with Unpolarized Light
  Phys. Rev. Lett. 126, 177201 (2021) [Crossref]
• Losada et al., Ultrafast control of spin interactions in honeycomb antiferromagnetic insulators
  Phys. Rev. B 100, 060410 (2019) [Crossref]
• Ke et al., Floquet-driven indirect exchange interaction mediated by topological insulator surface states
  Phys. Rev. B 110, 035307 (2024) [Crossref]
• Quito et al., Floquet engineering multichannel Kondo physics
  Phys. Rev. B 108, 155120 (2023) [Crossref]
• Takasan et al., Control of magnetic and topological orders with a DC electric field
  Phys. Rev. B 100, 060408 (2019) [Crossref]
• Curtis et al., Dynamics of photoinduced ferromagnetism in oxides with orbital degeneracy
  Phys. Rev. Research 5, 013204 (2023) [Crossref]
• Fabiani et al., Ultrafast dynamics of entanglement in Heisenberg antiferromagnets
  Phys. Rev. B 105, 094438 (2022) [Crossref]
• Chaudhary et al., Orbital Floquet engineering of exchange interactions in magnetic materials
  Phys. Rev. B 100, 220403 (2019) [Crossref]
• Vinas Boström et al., Light-induced topological magnons in two-dimensional van der Waals magnets
  SciPost Phys. 9, 061 (2020) [Crossref]
• Quito et al., Polarization as a tuning parameter for Floquet engineering: Magnetism in the honeycomb, square, and triangular Mott insulators
  Phys. Rev. B 103, 134435 (2021) [Crossref]
• Szilva et al., Quantitative theory of magnetic interactions in solids
  Rev. Mod. Phys. 95, 035004 (2023) [Crossref]
• Araujo et al., Unveiling ferromagnetism and antiferromagnetism in two dimensions at room temperature
  J. Phys. D: Appl. Phys. 55, 283003 (2022) [Crossref]