NovelTopo · Novel topological phases of matter: From topological invariants to experiments

Novel topological phases of matter: From topological invariants to experiments

When macroscopic quantum systems are cooled down to temperatures close to absolute zero, new phases of matter emerge from the collective organization of their microscopic constituents. Topological phases are among the most exotic states of quantum matter that emerge in this way. These phases of matter are distinguished from every other by the fact that their ground state wavefunction is characterized by a topological invariant that guarantees many special physical properties. While several proposed such phases have been studied since decades, the recent realization of topological insulators has kicked off a series of discoveries greatly enlarging the amount of topological phases at our disposal. These materials can be exploited for many applications, for example in spintronics, and can serve as a platform to realize even more exotic phases like topological superconductivity and Majorana fermions, the key building block of a topological quantum computer. The purpose of this project is to identify novel, robust properties of topological phases that can serve to identify them, to motivate material realizations of these phases by making predictions for realistic materials, and to collaborate with experimentalists in the discovery of such materials and their properties. The objectives of the project are as follows. First, we aim to propose novel platforms for the realization and manipulation of Majorana fermions. A particular focus is on platforms that may realize a large number of coupled Majorana states, that can open the path to realize the holographic Sachdev-Ye-Kitaev model. Second, we will determine the unique signatures that characterize topological Weyl semimetals. Specific aims include to study how the monopole charge of a Weyl semimetal can be accessed experimentally via photocurrent effects, and to study generalizations of Weyl semimetals in chiral lattices where the effect can be observed. A general analysis of the topological structure of photovoltaic responses will be performed to identify further robust signatures of other topological phases. Finally, the third objective is to study smoking gun signatures of magnetic Weyl semimetals, such as the Anomalous Hall Effect and the dynamics of spin-waves coupled to Weyl fermions, in the magnetic material EuCd2As2.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз