Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - SuperSpinHyMol (Modelling superconductivity and spin-related effects in hybrid molecular/two-dimensional materials)

Teaser

At the intersection of materials science, solid-state physics and quantum chemistry, research on two-dimensional (2D) layered materials and their van der Waals (vdW) heterostructures have been attracting enormous attention. The fascination for this new generation of materials...

Summary

At the intersection of materials science, solid-state physics and quantum chemistry, research on two-dimensional (2D) layered materials and their van der Waals (vdW) heterostructures have been attracting enormous attention. The fascination for this new generation of materials, with only a few nanometers thickness, arose from the extraordinary properties that appear when reducing dimensionality and the potential that these properties can offer for the next generation of nanodevices. In particular, the development of hybrid vdW heterostructures that combine a sublimable molecular magnetic material deposited on top of a superconducting monolayer is a promising pathway to create coherent bound states, which are interesting for future advances in molecular spintronics and quantum technologies. However, the understanding and control of the spin dynamics at the nanoscale is an essential step towards the successful design of this kind of materials in order to preserve the encoded quantum information.

The project SuperSpinHyMol had as a main objective the development of a full theoretical and computational framework for the rational design of a new generation of hybrid molecular/2D nanodevices with the aim of coupling coherently distant molecular spin qubits via interface states that can be tuned by chemical engineering. Thus, through this project we have explored the electronic, magnetic and superconducting properties of (a) novel molecular nanomagnets, (b) transition metal dichalcogenides (TMDs) and transition metal trihalides (TMHs) layered materials as a function of dimensionality and (c) hybrid vdW heterostructures by combination of them. In line with the main objectives of the proposed action, state-of-the-art first principles combined with effective ligand field calculations have been performed, predicting and modelling the magneto-structural properties of new magnetic materials, exploring their transport properties and investigating spin-related effects on the interface of hybrid molecular/2D materials.

Work performed

Firstly, we predicted the magnetic behavior of a new family of sublimable chloroquinolinate lanthanoid complexes and investigated their performance deposited on different inorganic substrates. This methodology was also applied to other molecular nanomagnets, enriching the diversity of families of magnetic systems that can be incorporated into 2D heterostructures. Through this process we also contributed to the physical understanding of some of their decoherence processes, in particular, the key role of vibrations in spin-relaxation processes and the effect of magnetic noise. Regarding 2D and vdW layered materials, we investigated in collaboration with an experimental group the gas sensing properties of a hybrid WS2 material in the presence of different gas species. Subsequently, we explored intralayer and interlayer magnetic interactions in the recently discovered 2D ferromagnets such as CrI3, analyzing their relation with different stackings in bilayers by means of Hubbard-corrected density functional theory calculations. The final step was the modelling of the formation of Yu-Shiba Rusinov bound states, which are sub-gap coherent states of interest in quantum computing, around point defects in 2H-NbSe2, as well as at the interface of hybrid van der Waals heterostructures containing a molecular layer and a NbSe2 monolayer.

The above-mentioned research results have been presented in the following international conferences, workshops, symposiums and seminars (selected):

2019

7th Workshop on 2D Materials. Elche, Spain. “First principles studies on van der Waals magnetic systems” (Invited talk)
Joint Symposium of Nanocohybri and Molspin Cost Actions: Hybrid Devices based on Superconductors and on Molecular Spins. Lisboa, Portugal. “Electronic structure and magnetic anisotropy: from molecular nanomagnets to 2D materials” (Invited talk)
Invited Seminar at Jacobs University (invited by Prof. Kortz). Bremen, Germany. “Lanthanide single-ion magnets and molecular spin qubits based on polyoxometalates”.
Invited Seminar at Universidad Santiago de Chile (invited by Dr. Aravena). Santiago, Chile. “Electronic Structure and Magnetic Anisotropy: from Molecular Nanomagnets to 2D Materials”

2018
43th International Conference on Coordination Chemistry (ICCC). Sendai, Japan. “Lanthanide single-ion magnets and molecular spin qubits based on polyoxometalates” (Contributed talk)
16th International Conference on Molecule-Based Magnets (ICMM). Rio de Janeiro, Brazil. (Poster)
Rising star ICMM2018 Pre-Conference. Rio de Janeiro, Brasil. “Spin states, vibrations and spin relaxation in molecular nanomagnets” (Invited talk)
International Symposium on Metal-Oxo Cluster Sciences: Exploring Novel Possibilities. Tokyo, Japan. “Lanthanide single-ion magnets and molecular spin qubits based on polyoxometalates” (Invited talk)
Invited Seminar at ICMol, University of Valencia (invited by Prof. Coronado). Valencia, Spain. “Introduction to DFT and application to layered materials”.

2017
C2TM Workshop on Advanced Materials & CheMat Doctoral Programme. Lisboa, Portugal. “Rational design and modelling of f-block single-ion magnets” (Invited talk)


The ER also participated in DESY Open Day and Science Night 2017 and shared scientific knowledge and an overview to his research to a general public through informal conversations. More than 10,000 visitors attended this event.

Two popular science articles were written and published in Investigación y Ciencia (“Viaje a universo de dos dimensiones” in September 2018) and Spektrum der Wissenchaft (“Zweidimensional Revolution” in November 2019), the Spanish and German versions of Scientific American, respectively.

Final results

These successful results will pave the way for the development of novel advanced materials based on the combination of a molecular or 2D nanomagnet with transition metal dichalcogenides. The theoretical and computational work carried out in this project is expected to have a broad impact in the two main research fields in which the action was framed (molecular magnetism and 2D materials), providing a better understanding of spin relaxation and interlayer interactions. The combination of the different experience of the host and the experienced researcher, as well as the efficient transfer-of-knowledge between them, has proven to be key for the development of the action. In particular, the combination of first principles with ligand field approaches has resulted in a very efficient tool to screen the potential of the magnetic molecular systems and their relaxation times. In parallel, the application of self-consistent Hubbard U determination has been crucial to advance towards the understanding of the electronic and magnetic properties of d-electrons in inorganic layered materials. Thus, though the project is basic science, the combination of the ingredients that have been investigated in the project, namely, molecular nanomagnets, 2D ferromagnets (CrI3) and 2D superconductors (NbSe2), is likely to have a long-term potential as new research by the scientific community is rapidly reported in both hot topics. The direct results of the project will contribute to an enhanced understanding of the magnetic relaxation of molecular nanomagnets and the effect of their spins at the interfaces of hybrid molecular/2D materials.

Website & more info

More info: https://www.mpsd.mpg.de/person/59276/2736.