10 papers
Irreducible Architectures of Multipartite Entanglement
Augusto Smerzi, Manuel Gessner
Multipartite entanglement is commonly characterized by scalar notions such as separability and entanglement depth, which do not resolve the distribution of entangled cluster sizes.…
Maximal Fisher Budget Forces Blind Directions in Bipartite Collective SU(d) Metrology
Tariq Aziz, Naeem Akhtar, Dong Wang +1
For pure two-qudit probes used in a single fixed setting to estimate a common SU(d) transformation, maximal total Fisher sensitivity and full local identifiability are mutually exc…
Hong-Ou-Mandel interference of more than 10 indistinguishable atoms
Martin Quensen, Mareike Hetzel, Luis Santos +4
When two indistinguishable bosons interfere at a beam splitter, they both exit through the same output port. This foundational quantum-mechanical phenomenon, known as the Hong-Ou-M…
Global Bounds beyond Local Quantum Metrology
Hai-Long Shi, Augusto Smerzi
Quantum Cramér--Rao theory is intrinsically local: it bounds precision near a specified parameter value, and its saturating measurement generally depends on that value. Barankin-t…
Robust spin-squeezing with random interaction graphs: the lesson from universality
Andrea Solfanelli, Augusto Smerzi, Peter Zoller +1
We establish the conditions under which scalable spin squeezing can be achieved in interacting spin ensembles embedded in arbitrary, inhomogeneous graph geometries. We identify two…
Adversarial Stress Tests for Quantum Certification
Veronica Sanz, Augusto Smerzi
We develop a practical framework for semi-device-independent (SDI) certification under operational deviations from the ideal protocol model. Apparent violations of classical benchm…