Non-perturbative treatment of giant atoms using chain transformations

Abstract

Superconducting circuits coupled to acoustic waveguides have extended the range of phenomena that can be experimentally studied using tools from quantum optics. In particular giant artificial atoms permit the investigation of systems in which the electric dipole approximation breaks down and pronounced non-Markovian effects become important. While previous studies of giant atoms focused on the realm of the rotating-wave approximation, we go beyond this and perform a numerically exact analysis of giant atoms strongly coupled to their environment, in regimes where counterrotating terms cannot be neglected. To achieve this, we use a Lanczos transformation to cast the field Hamiltonian into the form of a one-dimensional chain and employ matrix-product state simulations. This approach yields access to a wide range of system-bath observables and to previously unexplored parameter regimes.

8+5 pages, 8+2 figures, 1+1 tables. v3: update published version

References in corpus (10)

• The density-matrix renormalization group in the age of matrix product states
• The numerical renormalization group method for quantum impurity systems
• Exact mapping between system-reservoir quantum models and semi-infinite discrete chains using orthogonal polynomials
• Multiple Rabi Splittings under Ultra-Strong Vibrational Coupling
• Scattering in the ultrastrong regime: nonlinear optics with one photon
• Beyond Strong Coupling in a Massively Multimode Cavity
• Giant atoms with time-dependent couplings
• Modelling quantum light-matter interactions in waveguide-QED with retardation and a time-delayed feedback: matrix product states versus a space-discretized waveguide model
• Nonperturbative Waveguide Quantum Electrodynamics
• Convergence guarantees for discrete mode approximations to non-Markovian quantum baths

Cited by in corpus (5)

• Non-Markovian disentanglement dynamics in double-giant-atom waveguide-QED systems
• Giant atoms with time-dependent couplings
• Ultrastrong waveguide QED with giant atoms
• Functional Renormalization Group Approach to Circuit Quantum Electrodynamics
• Probing dressed states and quantum nonlinearities in a strongly coupled three-qubit waveguide system under optical pumping