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Layered materials host various collective quantum states such as intertwined electronic spatial orders, superconductivity or topological spin liquids. I will present two examples from our recent work, which are concerned with then manipulation of such collective quantum states. The first example is the laser-induced metal-insulator transition of 1T-TaS2, which is currently discussed intensively in relation to a somewhat enigmatic hidden state. Our experiments reveal the microscopic nature of this hidden state and show that the non-thermal metal-insulator transition of 1T-TaS2 corresponds to a transition between two long-range ordered electronic crystals. The second example is alpha-RuCl3 - a candidate material for Kitaev magnetism and the corresponding spin-liquid ground state. However, at ambient pressure and low temperatures this material does not exhibit a spin-liquid phase, but antiferromagnetic long-range order. We discovered a high-symmetry rhombohedral phase of alpha-RuCl3 at non-ambient pressure, which may indeed support a Kitaev spin-liquid ground state.

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Jochen Geck, TU Dresden
Seminar Room of the Institute of Physics II
Contact: M. Grüninger