Isotopic purification and hyperfine noise
Removing spinful isotopes can reduce nuclear-spin noise.
$$H_{\rm hf}=\sum_j A_j\mathbf S\cdot\mathbf I_j$$
Physical intuition
Removing spinful isotopes can reduce nuclear-spin noise.
Deep dive: physical mechanism
A nuclear-spin bath creates fluctuating effective magnetic fields.
What is measured experimentally?
Ramsey and echo decay reveal bath-induced dephasing.
Assumptions, noise and limitations
Charge and electrical noise remain even in isotopically purified material.
Research and simulation exercise
Simulate quasistatic Overhauser-field dephasing.
Connect the ideas
Explore the chapter overview, learning path, and references.