290S/290K Quantum Materials Seminar speaker Thais Victa Trevisan (new to UCB!) Wednesday, November 2 at 2 pm in Physics South 402

Time/Venue Wednesday, November 2 at 2 pm in Pacific time in 402 Physics South and via Zoom:
https://berkeley.zoom.us/j/99523499113pwd=REovb3pyam03WXQwbEhrU3dqNHZvdz09
Meeting ID: 995 2349 9113 Passcode: 600704
Host Joel Moore
Title Tuning magnetic symmetries and topology with bicircular light
Abstract Light-matter interaction is a powerful tool to manipulate the electronic properties of materials. Coherent light can be carefully tailored to break selected symmetries and stabilize phases of matter otherwise absent. This technique is called Floquet engineering and has received increasing attention in condensed matter physics in the past few years. In this talk, we theoretically analyze the effects of shining a bicircular light (BCL) on Dirac semimetals and topological insulators. BCL consists of a superposition of two circularly polarized light beams with frequencies that are integer multiples of each other. The resulting electric field traces a rose curve whose shape and orientation can be controlled by light parameters. A distinctive feature of BCL is its capability to simultaneously break time-reversal and spatial inversion symmetry, which leads to the realization of sought-after magnetic topological states. Another outcome of BCL driving is a dynamical tunability of the position and energy of topologically protected nodes of the band structure, resulting in a controlled modulation of the gyrotropic magnetic effect.