Advanced materials and advanced techniques

The study of strongly correlated materials such as heavy fermion clathrates and quantum magnets has been under the focus of fundamental material research. By studying these systems it is possible to reach new forms of quantum matter and further move the frontier of understanding the influence of strong electron correlations. Aside from the progress in basic science, these systems have recently been found to offer promising industrial applications. Quantum magnets are insulators that, under proper conditions, show large anisotropy of thermal conductivity. This is quite beneficial for e.g. CPU heatsinks that can drain excess heat more efficiently without self-heating effect present in cubic systems [1,2]. On the other hand, heavy fermion clathrates are intermetallic compounds (conductors) where thermopower, i.e. electricity generated by heat, can be largely increased due to coupling of several degrees of freedom [3]. This means that one can more efficiently harvest the heat generated by e.g. electronics, or car braking, and return a portion of it back to the system in the form of electricity. Such property can give way to smart new systems that preserve energy already on a microscopic scale.

To understand how these systems function we use a microscopic probe such as nuclear magnetic resonance (NMR) and subject them to extreme conditions – ultralow temperatures and high pressures. For this we have to use advanced materials that allow us to isolate a specific property of the material and find its connection to the physics behind it. Also, we have to develop innovative cryo-cooled amplifiers to reach a better signal-to-noise ratio of the measured data.

Here, we will present several materials from the above-mentioned classes we plan to study and research methods that will help us understand them completely.

References:

[1] Ch. Orfanidou and J. Giapintzakis, IEEE Trans. Electron Devices 60, 3330 (2013).
[2] C. Hess et al., Phys. Rev. B 64,184305 (2001).
[3] A. Prokofiev et al., Nature Mat. 12, 1096 (2013).