5 papers
Self-adjoint extensions of -photon light-matter Hamiltonians
Felix Fischer, Felix Knapp, Daniel Burgarth +1
Multiphoton light-matter interactions, in which a bosonic mode exchanges excitations at a time with a quantum system, are a source of genuine nonlinearity in quantum optics and…
Essentially singular limits of Jacobi operators and applications to higher-order squeezing
Felix Fischer, Daniel Burgarth, Davide Lonigro
We study a family of Jacobi operators in which the diagonal entries are multiplied by a coupling parameter . Under suitable conditions, the operator is self-adjoint for ev…
Quantum particle in the wrong box (or: the perils of finite-dimensional approximations)
Felix Fischer, Daniel Burgarth, Davide Lonigro
When numerically simulating the unitary time evolution of an infinite-dimensional quantum system, one is usually led to treat the Hamiltonian as an "infinite-dimensional matrix…
Finite-dimensional approximations of generalized squeezing
Sahel Ashhab, Felix Fischer, Davide Lonigro +2
We show unexpected behaviour in simulations of generalized squeezing performed with finite-dimensional truncations of the Fock space: even for extremely large dimension of the stat…
Self-adjoint realizations of higher-order squeezing operators
Felix Fischer, Daniel Burgarth, Davide Lonigro
Higher-order squeezing captures non-Gaussian features of quantum light by probing moments of the field beyond the variance, and is associated with operators involving nonlinear com…