Solid-state $^3\mathrm{He}$ NMR of the superconducting rubidium endofulleride $\mathrm{Rb_3(^3He@C_{60})}$

Murari Soundararajan; George R. Bacanu; Francesco Giustiniano; Mark C. Walkey; Gabriela Hoffman; Marina Carravetta; Martin R. Lees; Richard J. Whitby; Malcolm H. Levitt

arXiv · 2308.12812

Solid-state $^3\mathrm{He}$ NMR of the superconducting rubidium endofulleride $\mathrm{Rb_3(^3He@C_{60})}$

Murari Soundararajan·George R. Bacanu·Francesco Giustiniano·Mark C. Walkey·Gabriela Hoffman·Marina Carravetta·Martin R. Lees·Richard J. Whitby·Malcolm H. Levitt

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Abstract

A new variant of the superconducting fulleride $\mathrm{Rb_{3}C_{60}}$ is presented, with $\mathrm{^{3}He}$ atoms encapsulated in the $\mathrm{C_{60}}$ cages. The $\mathrm{^{3}He}$ nuclei act as sensitive NMR probes embedded in the material. The superconducting and normal states are characterised by $\mathrm{^{3}He}$ NMR. Evidence is found for co-existing vortex liquid and vortex solid phases below the superconducting transition temperature. A strong dependence of the spin-lattice relaxation time constant on spectral frequency is observed in the superconducting state, as revealed by two-dimensional NMR utilising an inverse Laplace transform. Surprisingly, this phenomenon persists, in attenuated form, at temperatures well above the superconducting transition.

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Murari Soundararajan, George R. Bacanu, Francesco Giustiniano, Mark C. Walkey, Gabriela Hoffman, Marina Carravetta, Martin R. Lees, Richard J. Whitby, Malcolm H. Levitt. 2023-08-24. Solid-state $^3\mathrm{He}$ NMR of the superconducting rubidium endofulleride $\mathrm{Rb_3(^3He@C_{60})}$. https://arxiv.org/abs/2308.12812

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