November 10th
when: Tuesday 10/11/2020, 12:45
where: KE D201 and Zoom meeting!
speaker: Marcelo Jaime
Title: Magnetic quantum matter in extreme magnetic field environments
abstract:
Quantum Matter research is a fast-growing field at the nodes of converging topical areas of current scientific interest including condensed matter physics, nano- and mesoscale phenomena, quantum information, quantum gravity, and string theory. In the context of materials, quantum behavior refers to properties that, while not present in the constituent parts, emerge as a result of strong interactions among the parts and are governed by quantum mechanics. In this presentation, I will discuss in some detail the scope of our research program on Quantum Matter in extreme magnetic field environments to H » 100T at the Los Alamos National Laboratory Pulsed Field Facility (LANL-PFF), a branch of the National High Magnetic Field Laboratory (NHMFL). I will describe recent results in the study of quantum matter through the crystal lattice, i.e. with high-resolution optical interference-based fiber Bragg grating (FBG) dilatometry. The interplay of geometrical frustration, dimensionality, and competing energy scales often leads to exotic states, such as spin-liquids, -glasses, and –supersolids, and complex magnetic textures. Two of the materials we have focused on are BaCuSi2O6 and SrCu2(BO3)2, good examples of spin-1/2 Heisenberg antiferromagnets. The former in a square bi-layer lattice, the later in the archetypical Shastry-Sutherland lattice. While un-frustrated BaCuSi2O6 is an almost-ideal case for Bose-Einstein condensation of magnons, strongly frustrated SrCu2(BO3)2 exhibits a rich spectrum of magnetization plateaus and stripe-like magnetic textures in applied fields, and some of them are candidates for exotic states. We elucidated the spin-lattice mechanisms behind the extraordinary stability of magnetic plateaus, and observed the formation of bound collective states upon the intentional addition of impurities. Quantum spin liquids, a new state of matter proposed to exist in strongly frustrated systems, will be briefly introduced.