I will present recent experiments\, and exciting new di rections\, for the use of high-spin nuclei in silicon for quantum info rmation\, quantum foundations\, and spin-mechanics entanglement. Nucle ar spins in silicon are among the most coherent quantum objects to be found in the solid state. They have infinite relaxation time\, and sec ond-scale coherence time [1]. By using the I=7/2\, 8-dimensional nucle us of antimony [2]\, we have prepared a nuclear Schroedinger cat withi n 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. \nWe then used this and other nonclassical states to perform a curious experime nt\, where the quanutmness of the state is certified by monitoring its uniform precession\, in seeming contradiction with Ehrenfest's theore m [4]. \nHigh-spin nuclei possess a quadrupole moment that couples th em to lattice strain [5]. I will discuss plans to entangle a single nu clear spin with a MHz-range mechanical oscillator\, and perspectives t o scale up the mass of the oscillator to test gravitational collapse m odels. \n[1] J. Muhonen et al.\, Nature Nanotechnology 9\, 986 (2014) \n[2] S. Asaad\, V. Mourik et al.\, Nature 579\, 205 (2020) \n[3] X. Y u et al.\, Nature Physics 21\, 362 (2025) \n[4] A. Vaartjes et al.\, N ewton 1\, 100017 (2025) \n[5] L. O'Neill et al.\, Applied Physics Lett ers 119\, 174001 (2021) \n
\nThis event starts at 2:30pm with r efreshments\, followed at 2:45pm by a short presentation by Brighton C oe (Eriksson group)\, titled "Light-induced offset charge in Si/SiGe q uantum dots as a proxy for radiation impacts". The invited presentatio n starts at 3pm.
URL:https://www.physics.wisc.edu/events/?id=8837 END:VEVENT END:VCALENDAR