Tuning Topological Materials by hydrostatic Pressure and uniaxial Stress

The discovery of topological phases of matter has driven the attention of great part of the solid-state science community due to its high for future applications, led by the presence of unusual electronic properties, such as extreme large magnetoresistance and anomalous Hall effect. However, topological phases on Ce-based nonsymmorphic materials are rather unexplored.

The nonsymmorphic crystalline structure may create band crossings, which are needed for the existence of non-trivial topological phases, while the presence of magnetic Ce ions gives rise to many complex effects, such as magnetism and the Kondo effect.

These correlated phenomena result in a promising route to pin the band crossings of nonsymmorphic compounds close to the Fermi level, favoring non-trivial topological effects in transport properties, which may lead to the realization of new spintronic devices.

This proposal aims to understand the interplay between strong electronic correlations and non-trivial topological phases in Ce-based compounds.

To achieve that hydrostatic pressure and/or uniaxial stress will be used to tune the electronic bands, i.e. moving the band crossings towards the Fermi energy and/or modify the bandstructure, and the magnetic correlations in Ce-based nonsymmorphic compounds, such as CeAlGe and CeSbTe.

By performing electrical transport experiments under applied pressure/stress and in magnetic fields, the evolution and interrelation between non-trivial topological phases and strong electronic correlations will be investigated.

As part of the experimental work, a new technique will be developed, which combines micro-structured samples with Bridgman or diamond anvil cells. This method will enable the simultaneous realization of magnetoresistance and Hall measurements up to more than 30 GPa.

Our findings will significantly enhance the knowledge in strongly correlated electrons systems and topological materials, two fundamental areas of condensed matter physics.