Palestrante: Prof. Dr. Ricardo Reis (EMA/LNLS)
Título: Understanding Quantum Materials by X-Ray Techniques under extreme conditions
Data: 11/11 às 16h
Resumo: Many of today’s most exciting and potentially useful materials display states of matter that seem to be explicable only by applying quantum mechanical models. This is perhaps unsurprising as these materials can be host to a complex medley of ingredients that include many-body interactions between spins, electrons and phonons. The ground states frequently exhibit cooperative properties, such as superconductivity, charge or spin-order, Kondo effect, or exotic excitations such as Weyl or Majorana fermions. Besides the fundamental interest in understanding such materials, there is also the prospect of controlling their properties and putting them to use. Therefore, deciphering what causes quantum states of matter to form remains one of the most pressing challenges facing modern physics. In this talk, I will highlight how we can shed light on the building blocks of these materials by a combination of synchrotron techniques (x-ray absorption, diffraction, and scattering) with external pressure (hydrostatic and uniaxial), low temperature and high magnetic ﬁeld in order to enable a continuous, clean and reversible tuning of quantum correlations. Our aim with is to drive materials through the critical region where the state of matter changes and inherently quantum eﬀects dominate in order to probe the electronic, magnetic and structural properties as a function of lattice contraction. For that I will focus on materials that are on the verge of a phase instability with distinct crystalline structures and with electronic behavior displaying nontrivial topology.