2001/01/31 by Sohrab Ismail‐Beigi, Sohrab Ismail-Beigi, Eric K. Chang +1 · 75 citations
Physics and Astronomy · #Classical mechanics #Computation #Computer science #Coupling (piping) #Degrees of freedom (physics and chemistry) #Electromagnetic field #Electron #Feynman diagram #Gyrotron and Vacuum Electronics Research #Nonlinear system #Path integral formulation #Physics #Quantum #Quantum and electron transport phenomena #Quantum electrodynamics #Quantum entanglement #Quantum mechanics #Quantum nonlocality #Quantum, superfluid, helium dynamics #Theoretical physics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.87.087402
published in Physical Review Letters 87(8), 087402 (American Physical Society) · 1 figure, 1 table
arxiv created 2001/06/20 · openalex publication_date 2001/08/03 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Nonlocal Hamiltonians are used widely in first-principles quantum calculations; the nonlocality stems from eliminating undesired degrees of freedom, e.g., core electrons. To date, attempts to couple nonlocal systems to external electromagnetic (EM) fields have been heuristic or limited to weak or long wavelength fields. Using Feynman path integrals, we derive an exact, closed-form coupling of arbitrary EM fields to nonlocal systems. Our results justify and clarify the couplings used to date and are essential for systematic computation of linear and especially nonlinear responses.