Spin Squeezing, Macrorealism and the Heisenberg uncertainty principle
PhD thesis — University of the Basque Country, 2015. Full text: https://archive.org/details/arxiv-1511.08104
Mechanisms
Spin Squeezing, Macrorealism and the Heisenberg uncertainty principle
Entanglement detection in big atomic ensembles is the backbone of quantum metrology — tighter detection criteria mean more precise quantum sensors and clocks.
New spin-squeezing inequalities for detecting entanglement in large ensembles of atoms outperform past approaches — especially for unpolarized states — and for symmetric states of spin-1/2 particles they are exactly equivalent to the PPT (partial-transpose) criterion; the thesis's larger aim is testing whether macroscopic systems violate classical principles like local-realism and macrorealism.
Why it matters
Entanglement detection in big atomic ensembles is the backbone of quantum metrology — tighter detection criteria mean more precise quantum sensors and clocks.
Use when: When the standard test can't see the states you care about, redesign the test — spin squeezing catches entanglement the usual criteria are blind to.