Ultra-fast control of magnetic relaxation in a periodically driven Hubbard model

Journal article

Motivated by cold atom and ultra-fast pump-probe experiments we study the melting of long-range antiferromagnetic order of a perfect Néel state in a periodically driven repulsive Hubbard model. The dynamics is calculated for a Bethe lattice in infinite dimensions with non-equilibrium dynamical mean-field theory. In the absence of driving melting proceeds differently depending on the quench of the interactions to hopping ratio math formula from the atomic limit. For math formula decay occurs due to mobile charge-excitations transferring energy to the spin sector, while for math formula it is governed by the dynamics of residual quasi-particles. Here we explore the rich effects that strong periodic driving has on this relaxation process spanning three frequency ω regimes: (i) high-frequency math formula, (ii) resonant math formula with integer l, and (iii) in-gap math formula away from resonance. In case (i) we can quickly switch the decay from quasi-particle to charge-excitation mechanism through the suppression of ν0. For (ii) the interaction can be engineered, even allowing an effective math formula regime to be reached, giving the reverse switch from a charge-excitation to quasi-particle decay mechanism. For (iii) the exchange interaction can be controlled with little effect on the decay. By combining these regimes we show how periodic driving could be a potential pathway for controlling magnetism in antiferromagnetic materials. Finally, our numerical results demonstrate the accuracy and applicability of matrix product state techniques to the Hamiltonian DMFT impurity problem subjected to strong periodic driving.

Authors: Mendoza-Arenas, JJ; Gómez-Ruiz, FJ; Eckstein, Martin; Jaksch, DH; Clark, SR

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Annalen der Physik
• Publication date: 2017-07-01
• Acceptance date: 2017-05-22
• DOI: 10.1002/andp.201700024
• Keywords: Ultrafast control; on-equilibrium dynamical mean-field theory; Floquet theory; antiferromagnetism