Perspective: Quantum Hamiltonians for Optical Interactions
arXiv:1801.07735 · doi:10.1063/1.5018399
Abstract
The multipolar Hamiltonian of quantum electrodynamics (QED) is extensively employed in chemical and optical physics to treat rigorously the interaction of electromagnetic fields with matter. It is also widely used to evaluate intermolecular interactions. The multipolar version of the Hamiltonian is commonly obtained by carrying out a unitary transformation of the Coulomb gauge Hamiltonian that goes by the name of Power-Zienau-Woolley (PZW). Not only does the formulation provide excellent agreement with experiment, and versatility in its predictive ability, but also superior physical insight. Recently, the foundations and validity of the PZW Hamiltonian have been questioned, raising a concern over issues of gauge transformation and invariance, and whether observable quantities obtained from unitarily equivalent Hamiltonians are identical. Here, an in-depth analysis of theoretical foundations clarifies the issues and enables misconceptions to be identified. Claims of non-physicality are refuted: the PZW transformation and ensuing Hamiltonian are shown to rest on solid physical principles and secure theoretical ground.
10 pages, 123 references. (in press)
References in corpus (12)
- Characterizing optical chirality
- Protecting a Spin Ensemble against Decoherence in the Strong-Coupling Regime of Cavity QED
- A macroscopic test of the Aharonov-Bohm effect
- Why you should not use the electric field to quantize in nonlinear optics
- Enhanced chiral discriminatory van der Waals interactions mediated by chiral surfaces
- Mathematical Methods in Quantum Optics: the Dicke Model
- Dynamical Casimir-Polder force on a partially dressed atom near a conducting wall
- Body-assisted van der Waals interaction between excited atoms
- Super- and subradiant emission of two-level systems in the near-Dicke limit
- On the Theory of Casimir-Polder Forces
- A dual-Lagrangian description adapted to quantum optics in dispersive and dissipative dielectric media
- Utilizing Microcavities to Suppress Third-order Cascades in Fifth-order Raman Spectra