Events

I will present recent experiments, and exciting new directions, for the use of high-spin nuclei in silicon for quantum information, quantum foundations, and spin-mechanics entanglement. Nuclear spins in silicon are among the most coherent quantum objects to be found in the solid state. They have infinite relaxation time, and second-scale coherence time [1]. By using the I=7/2, 8-dimensional nucleus of antimony [2], we have prepared a nuclear Schroedinger cat within a functional nanoelectronic device [3]. This can be used to encode a cat-qubit similar to the bosonic encodings used in microwave cavities, but with atomic size, and even more extreme noise bias. We then used this and other nonclassical states to perform a curious experiment, where the quanutmness of the state is certified by monitoring its uniform precession, in seeming contradiction with Ehrenfest's theorem [4]. High-spin nuclei possess a quadrupole moment that couples them to lattice strain [5]. I will discuss plans to entangle a single nuclear spin with a MHz-range mechanical oscillator, and perspectives to scale up the mass of the oscillator to test gravitational collapse models. [1] J. Muhonen et al., Nature Nanotechnology 9, 986 (2014) [2] S. Asaad, V. Mourik et al., Nature 579, 205 (2020) [3] X. Yu et al., Nature Physics 21, 362 (2025) [4] A. Vaartjes et al., Newton 1, 100017 (2025) [5] L. O'Neill et al., Applied Physics Letters 119, 174001 (2021)

This event starts at 2:30pm with refreshments, followed at 2:45pm by a short presentation by Brighton Coe (Eriksson group), titled "Light-induced offset charge in Si/SiGe quantum dots as a proxy for radiation impacts". The invited presentation starts at 3pm.