Colloquium: Alex McLeod, University of Minnesota; & Student Awards
Unveiling the Realm of Quantum Materials with Nano-optics
Abstract: Tool sets wielded by condensed matter researchers over the past century have expanded meteorically into frontiers of the ultra-small and ultra-fast, today leveraging advancements like atomically precise crystal growth, nano-scale device assembly, and femtosecond spectroscopy with ultrafast photon pulses. On the other hand, despite breathtaking 20th century advancements in photon sources and detection technologies, our capacity to resolve condensed matter through optical spectroscopies has remained largely arrested by the diffraction limit since its 19th century observation by Ernst Abbe. However, recent decades have seen the marriage of “conventional” optics with scanning probes to circumvent the diffraction limit, realizing a nanometer-resolved optical spectroscopy mediated fundamentally by electromagnetic near-fields. In this talk, I review and celebrate the breakthrough of this technique into regimes of low temperature and nanometer spatial scales necessary for fundamental studies of quantum materials. I showcase seminal investigations of collective excitations in 2-dimensional media like graphene, electronic phase competition in correlated electron solids, and on-demand control of optical properties in strongly interacting materials. I will share my ambitious perspectives for the future of nano-optical probes for quantum materials, a future that is simultaneously ultra-bright and ultra-small, and fundamentally transformative for optical spectroscopies of complex matter.