Optical control of competing exchange interactions and coherent spin-charge coupling in two-orbital Mott insulators
Barbeau MMS, Eckstein M, Katsnelson M, Mentink JH (2019)
Publication Type: Journal article
Publication year: 2019
Journal
Book Volume: 6
Journal Issue: 3
DOI: 10.21468/SciPostPhys.6.3.027
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(ex) that is analogous to the single-orbital case. Moreover we demonstrate that also the additional biquadratic exchange interaction B-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.
Authors with CRIS profile
Involved external institutions
Netherlands (NL)How to cite
APA:
Barbeau, M.M.S., Eckstein, M., Katsnelson, M., & Mentink, J.H. (2019). Optical control of competing exchange interactions and coherent spin-charge coupling in two-orbital Mott insulators. SciPost Physics, 6(3). https://dx.doi.org/10.21468/SciPostPhys.6.3.027
MLA:
Barbeau, Marion M. S., et al. "Optical control of competing exchange interactions and coherent spin-charge coupling in two-orbital Mott insulators." SciPost Physics 6.3 (2019).
BibTeX: Download