Quantum metrology with one-dimensional superradiant photonic states

Quantum metrology with one-dimensional superradiant photonic states

Seminar author:Martí Perarnau Llobet

Event date and time:05/30/2018 12:00:pm

Event location:GIQ Seminar Room (C5/262)

Event contact:marti.perarnau.llobet@gmail.com

Photonic states with large and fixed photon numbers, such as Fock states, enable quantum-enhanced metrology but remain an experimentally elusive resource. A potentially simple, deterministic and scalable way to generate these states consists of fully exciting N quantum emitters equally coupled to a common photonic reservoir, which leads to a collective decay known as Dicke superradiance. The emitted N-photon state turns out to be a highly entangled multimode state, and to characterise its metrological properties in this work we: (i) develop theoretical tools to compute the Quantum Fisher Information of general multimode photonic states; (ii) use it to show that Dicke superradiant photons in 1D waveguides achieve Heisenberg scaling, which can be saturated by a parity measurement; (iii) and study the robustness of these states to experimental limitations in state-of-art atom-waveguide QED setups.