SPICE Workshop on Non-equilibrium Quantum Materials Design, June 27th - 29th 2023
Wanzheng Hu
Multiferroics simultaneously exhibit ferroelectric and magnetic order that are intrinsically coupled to each other within a single phase. These couplings allow for the control of magnetization and polarization through respective cross-coupled electric and magnetic fields, which makes them appealing candidates for encoding and accessing information using two order parameters at a time.
Ultrashort laser pulses provide the possibility to generate large electric field strengths, which in turn allows for ultrafast switching of order parameters on sub-picosecond timescales. Experimental realization of intense terahertz (THz) and mid-infrared (MIR) pulses opens up new pathways for dynamical materials engineering. The strong electric fields of THz and MIR pulses are able to drive phonon oscillations with large amplitudes, where anharmonic contributions of the interatomic potential energy surface become important. These anharmonicities can be utilized to induce nonlinear phononic rectification, in which nonlinear coupling between phonon modes leads to a quasistatic distortion of the crystal structure, to induce transient crystal geometries that are not accessible in equilibrium. In this talk, I will present our recent results on the ultrafast manipulation of multiferroic BiFeO3 by nonlinear phononics.