Theory Seminar (High Energy/Cosmology) |
Events on Wednesday, October 21st, 2026
- Entanglement Limits on Coherent Enhancement
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Zach Bogorad, Fermilab
- Abstract: Coherent enhancement is a powerful mechanism for improving the sensitivity of a wide range of detectors, but its practical use is often limited by the difficulty of preparing the required quantum states. In this talk, I will show that this difficulty has a fundamental origin: coherent enhancement is quantitatively constrained by entanglement. I will present general bounds on how the strength of coherent effects can scale with system size, as a function of the single-mode entanglement entropy of the detector. These bounds smoothly interpolate between the incoherent and fully coherent regimes, and apply both to parameter-estimation problems and to scattering processes. I will discuss these results from two complementary perspectives: First, they appear as bounds on the quantum Fisher information of many-body states, which translate directly into limits on parameter sensitivity via the quantum Cramér–Rao bound. Second, they can be interpreted as limits on a class of scattering cross sections, leading to predictions for how minimum detectable interaction strengths scale with target size. Together, these results provide a unified view of coherent enhancement in metrology and scattering experiments, and motivate the development of new techniques for generating entangled detector states.
- Host: Josh Foster