Tommaso Tufarelli, from University of Nottingham, is visiting AQM from Tuesday 10 to Thursday 12 January.

He will deliver a talk on Wednesday, 11 January at 12:30 in Auletta Ottica Quantistica (5 piano LITA)

### Refining the Dicke Model

I will start by reviewing an interesting signature of the “A^2 term” in a simple Dicke model featuring two coupled oscillators [first reported in Phys. Rev. A 91, 063840 (2015)]. Then, I will discuss conditions under which such model could be derived as an approximation to a minimal coupling Hamiltonian in Coulomb-gauge, showing that some additional Hamiltonian terms, not usually discussed in the literature, should be present in the ultrastrong coupling regime.